CLEANUP: config: Return ERR_NONE from config callbacks instead of 0

Return ERR_NONE instead of 0 on success for all config callbacks that should
return ERR_* codes. There is no change because ERR_NONE is a macro equals to
0. But this makes the return value more explicit.

src/51d.c

@@ -625,7 +625,7 @@ static int init_51degrees(void)
 	fiftyoneDegreesDataSetInitStatus _51d_dataset_status = DATA_SET_INIT_STATUS_NOT_SET;
 
 	if (!global_51degrees.data_file_path)
-		return 0;
+		return ERR_NONE;
 
 	if (global.nbthread < 1) {
 		ha_alert("51Degrees: The thread count cannot be zero or negative.\n");
@@ -708,7 +708,7 @@ static int init_51degrees(void)
 	}
 #endif
 
-	return 0;
+	return ERR_NONE;
 }
 
 static void deinit_51degrees(void)

src/cache.c

@@ -1533,7 +1533,7 @@ int post_check_cache()
 	struct cache *back, *cache_config, *cache;
 	struct shared_context *shctx;
 	int ret_shctx;
-	int err_code = 0;
+	int err_code = ERR_NONE;
 
 	list_for_each_entry_safe(cache_config, back, &caches_config, list) {
 

src/check.c

@@ -1142,7 +1142,7 @@ static int start_checks()
 	}
 
 	if (!nbcheck)
-		return 0;
+		return ERR_NONE;
 
 	srand((unsigned)time(NULL));
 
@@ -1180,7 +1180,7 @@ static int start_checks()
 			}
 		}
 	}
-	return 0;
+	return ERR_NONE;
 }
 
 
@@ -1227,7 +1227,7 @@ static int init_srv_check(struct server *srv)
 {
 	const char *err;
 	struct tcpcheck_rule *r;
-	int ret = 0;
+	int ret = ERR_NONE;
 	int check_type;
 
 	if (!srv->do_check)
@@ -1353,7 +1353,7 @@ static int init_srv_agent_check(struct server *srv)
 {
 	struct tcpcheck_rule *chk;
 	const char *err;
-	int ret = 0;
+	int ret = ERR_NONE;
 
 	if (!srv->do_agent)
 		goto out;

src/da.c

@@ -119,7 +119,7 @@ static void da_haproxy_log(da_severity_t severity, da_status_t status,
  */
 static int init_deviceatlas(void)
 {
-	int err_code = 0;
+	int err_code = ERR_NONE;
 
 	if (global_deviceatlas.jsonpath != 0) {
 		FILE *jsonp;

src/debug.c

@@ -894,7 +894,7 @@ static int init_debug()
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_SIGINFO;
 	sigaction(DEBUGSIG, &sa, NULL);
-	return 0;
+	return ERR_NONE;
 }
 
 REGISTER_POST_CHECK(init_debug);

src/filters.c

@@ -288,7 +288,7 @@ static int
 flt_init_all()
 {
 	struct proxy *px;
-	int err_code = 0;
+	int err_code = ERR_NONE;
 
 	for (px = proxies_list; px; px = px->next) {
 		if (px->disabled) {

src/http_htx.c

@@ -2005,7 +2005,7 @@ static int proxy_check_errors(struct proxy *px)
 {
 	struct conf_errors *conf_err, *conf_err_back;
 	struct http_errors *http_errs;
-	int rc, err = 0;
+	int rc, err = ERR_NONE;
 
 	list_for_each_entry_safe(conf_err, conf_err_back, &px->conf.errors, list) {
 		if (conf_err->type == 1) {
@@ -2061,7 +2061,7 @@ static int post_check_errors()
 	struct ebpt_node *node;
 	struct http_error_msg *http_errmsg;
 	struct htx *htx;
-	int err_code = 0;
+	int err_code = ERR_NONE;
 
 	node = ebpt_first(&http_error_messages);
 	while (node) {

src/sink.c

@@ -972,7 +972,7 @@ int cfg_post_parse_ring()
 */
 int post_sink_resolve()
 {
-	int err_code = 0;
+	int err_code = ERR_NONE;
 	struct logsrv *logsrv, *logb;
 	struct sink *sink;
 	struct proxy *px;

src/ssl_sock.c

@@ -612,7 +612,7 @@ static int ssl_sock_register_msg_callbacks(void)
 	}
 #endif
 
-	return 0;
+	return ERR_NONE;
 }
 
 /* Used to free all SSL/TLS protocol message callbacks that were
@@ -1245,7 +1245,7 @@ static int tlskeys_finalize_config(void)
 	/* swap root */
 	LIST_ADD(&tkr, &tlskeys_reference);
 	LIST_DEL(&tkr);
-	return 0;
+	return ERR_NONE;
 }
 #endif /* SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB */
 
@@ -6306,7 +6306,7 @@ void ssl_free_global_issuers(void)
 
 #ifndef OPENSSL_NO_ENGINE
 static int ssl_check_async_engine_count(void) {
-	int err_code = 0;
+	int err_code = ERR_NONE;
 
 	if (global_ssl.async && (openssl_engines_initialized > 32)) {
 		ha_alert("ssl-mode-async only supports a maximum of 32 engines.\n");

src/tcpcheck.c

@@ -3470,7 +3470,7 @@ static int check_proxy_tcpcheck(struct proxy *px)
 	struct tcpcheck_rule *chk, *back;
 	char *comment = NULL, *errmsg = NULL;
 	enum tcpcheck_rule_type prev_action = TCPCHK_ACT_COMMENT;
-	int ret = 0;
+	int ret = ERR_NONE;
 
 	if (!(px->cap & PR_CAP_BE) || (px->options2 & PR_O2_CHK_ANY) != PR_O2_TCPCHK_CHK) {
 		deinit_proxy_tcpcheck(px);

src/wdt.c

@@ -174,7 +174,7 @@ int init_wdt()
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_SIGINFO;
 	sigaction(WDTSIG, &sa, NULL);
-	return 0;
+	return ERR_NONE;
 }
 
 REGISTER_POST_CHECK(init_wdt);

src/wurfl.c

@@ -263,7 +263,7 @@ static int ha_wurfl_init(void)
 	// wurfl-data-file not configured, WURFL is not used so don't try to
 	// configure it.
 	if (global_wurfl.data_file == NULL)
-		return 0;
+		return ERR_NONE;
 
 	ha_notice("WURFL: Loading module v.%s\n", HA_WURFL_MODULE_VERSION);
 	// creating WURFL handler
@@ -395,7 +395,7 @@ static int ha_wurfl_init(void)
 
 	ha_notice("WURFL: Engine loaded\n");
 	ha_notice("WURFL: Module load completed\n");
-	return 0;
+	return ERR_NONE;
 }
 
 static void ha_wurfl_deinit(void)