Add missing WSREP(thd) condition and remove unnecessary DBUG_RETURN.

sql/sql_alter.cc

@@ -308,7 +308,8 @@ bool Sql_cmd_alter_table::execute(THD *thd)
 #ifdef WITH_WSREP
   TABLE *find_temporary_table(THD *thd, const TABLE_LIST *tl);
 
-  if ((!thd->is_current_stmt_binlog_format_row() ||
+  if (WSREP(thd) &&
+      (!thd->is_current_stmt_binlog_format_row() ||
        !find_temporary_table(thd, first_table)))
   {
     WSREP_TO_ISOLATION_BEGIN_ALTER(((lex->name.str) ? select_lex->db : NULL),
@@ -329,8 +330,6 @@ bool Sql_cmd_alter_table::execute(THD *thd)
                             lex->ignore);
 
   DBUG_RETURN(result);
-
-  DBUG_RETURN(result);
 #ifdef WITH_WSREP
 error:
   {