Fix reduce usage with max function.

The (reduce #'max ...) requires an initial value to be provided, as the max
function wants at least 1 argument, as we can see here:

CL-USER> (handler-case (reduce #'max nil) (condition (e) (format t "~a" e)))
Too few arguments in call to #<Compiled-function MAX #x300000113C2F>:
0 arguments provided, at least 1 required.

src/pgsql/pgsql-ddl.lisp

@@ -49,7 +49,8 @@
             (let ((max (reduce #'max
                                (mapcar #'length
                                        (mapcar #'column-name
-                                               (table-column-list table))))))
+                                               (table-column-list table)))
+                               :initial-value 0)))
               (loop
                  :for (col . last?) :on (table-column-list table)
                  :do (progn

src/utils/catalog.lisp

@@ -375,7 +375,8 @@
 
 (defmethod max-indexes-per-table ((catalog catalog) &key)
   "Count how many indexes maximum per table are listed in SCHEMA."
-  (reduce #'max (mapcar #'max-indexes-per-table (catalog-schema-list catalog))))
+  (reduce #'max (mapcar #'max-indexes-per-table (catalog-schema-list catalog))
+          :initial-value 0))
 
 ;;;
 ;;; Not a generic/method because only used for the table object, and we want

src/utils/report.lisp

@@ -192,7 +192,8 @@
                           (append (pgstate-tabnames data)
                                   (pgstate-tabnames pre)
                                   (pgstate-tabnames post)
-                                  (list legend))))))
+                                  (list legend))))
+          :initial-value 0))
 
 (defun report-full-summary (legend sections total-secs)
   "Report the full story when given three different sections of reporting."