Polishing: after implementing TRIGGER privilege, mysqld option

'--log-bin-trust-function-creators' affects not only replication of the
stored functions, but also replication of the triggers.


sql/mysqld.cc:
  Updated the description of mysqld '--log-bin-trust-function-creators' option
  to reflect that after introducing TRIGGER privilege this option also controls
  replication of triggers.
sql/sql_trigger.cc:
  Updated the comment to be consistent with the new behaviour,
  introduced by TRIGGER privilege.

sql/mysqld.cc

@@ -5234,8 +5234,8 @@ Disable with --skip-innodb-doublewrite.", (gptr*) &innobase_use_doublewrite,
   */
   {"log-bin-trust-function-creators", OPT_LOG_BIN_TRUST_FUNCTION_CREATORS,
    "If equal to 0 (the default), then when --log-bin is used, creation of "
-   "a function is allowed only to users having the SUPER privilege and only "
-   "if this function may not break binary logging."
+   "a function (a trigger) is allowed only to users having the SUPER privilege "
+   "and only if this function (trigger) may not break binary logging."
 #ifdef HAVE_ROW_BASED_REPLICATION
    " If using --binlog-format=row, the security issues do not exist and the "
    "binary logging cannot break so this option is automatically set to 1."

sql/sql_trigger.cc

@@ -195,10 +195,8 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create)
   /*
     There is no DETERMINISTIC clause for triggers, so can't check it.
     But a trigger can in theory be used to do nasty things (if it supported
-    DROP for example) so we do the check for privileges. For now there is
-    already a stronger test right above; but when this stronger test will
-    be removed, the test below will hold. Because triggers have the same
-    nature as functions regarding binlogging: their body is implicitely
+    DROP for example) so we do the check for privileges. Triggers have the
+    same nature as functions regarding binlogging: their body is implicitely
     binlogged, so they share the same danger, so trust_function_creators
     applies to them too.
   */