Change comment to describe correct lock level used

src/backend/commands/trigger.c

@@ -532,7 +532,7 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString,
 	 * can skip this for internally generated triggers, since the name
 	 * modification above should be sufficient.
 	 *
-	 * NOTE that this is cool only because we have AccessExclusiveLock on the
+	 * NOTE that this is cool only because we have ShareRowExclusiveLock on the
 	 * relation, so the trigger set won't be changing underneath us.
 	 */
 	if (!isInternal)