MINOR: servers: Provide a pointer to the server in srv_per_tgroup.

Add a pointer to the server into the struct srv_per_tgroup, so that if
we only have access to that srv_per_tgroup, we can come back to the
corresponding server.

include/haproxy/server-t.h

@@ -274,6 +274,7 @@ struct srv_per_thread {
 /* Each server will have one occurrence of this structure per thread group */
 struct srv_per_tgroup {
 	struct queue queue;			/* pending connections */
+	struct server *server;                  /* pointer to the corresponding server */
 	unsigned int last_other_tgrp_served;	/* Last other tgrp we dequeued from */
 	unsigned int self_served;		/* Number of connection we dequeued from our own queue */
 	unsigned int dequeuing;                 /* non-zero = dequeuing in progress (atomic) */

src/server.c

@@ -5805,8 +5805,10 @@ int srv_init_per_thr(struct server *srv)
 		LIST_INIT(&srv->per_thr[i].idle_conn_list);
 	}
 
-	for (i = 0; i < global.nbtgroups; i++)
+	for (i = 0; i < global.nbtgroups; i++) {
+		srv->per_tgrp[i].server = srv;
 		queue_init(&srv->per_tgrp[i].queue, srv->proxy, srv);
+	}
 
 	return 0;
 }