pg_stat_statements: Fix incorrect comment with entry resets

Oversight in 6b4d23f.

Author: Japin Li, Richard Guo
Discussion: https://postgr.es/m/MEYP282MB1669FC91C764E277821936D3B624A@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
Backpatch-through: 14

Author: michaelpq

contrib/pg_stat_statements/pg_stat_statements.c

@@ -2552,10 +2552,8 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 		if (entry)				/* found */
 			num_remove++;
 
-		/* Also remove entries for top level statements */
+		/* Also remove the top-level entry if it exists. */
 		key.toplevel = true;
-
-		/* Remove the key if exists */
 		entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_REMOVE, NULL);
 		if (entry)				/* found */
 			num_remove++;