Fix compilation warnings in -DWITH_WSREP=OFF build.

sql/event_data_objects.cc

@@ -1482,7 +1482,9 @@ end:
 
       WSREP_TO_ISOLATION_END;
 
+#ifdef WITH_WSREP
   error:
+#endif
       thd->tx_read_only= save_tx_read_only;
       thd->security_ctx->master_access= saved_master_access;
     }

sql/mysqld.cc

@@ -5730,7 +5730,9 @@ int mysqld_main(int argc, char **argv)
     }
   }
   else
+  {
     wsrep_init_startup (false);
+  }
 
  if (opt_bootstrap)
   {

sql/slave.cc

@@ -4406,7 +4406,9 @@ pthread_handler_t handle_slave_sql(void *arg)
   my_thread_init();
   DBUG_ENTER("handle_slave_sql");
 
+#ifdef WITH_WSREP
  wsrep_restart_point:
+#endif
 
   serial_rgi= new rpl_group_info(rli);
   thd = new THD; // note that contructor of THD uses DBUG_ !