fixup! Fixed compiler warnings from optimized builds

sql/sql_lex.h

@@ -3439,13 +3439,16 @@ struct LEX: public Query_tables_list
   {
     DBUG_ENTER("LEX::pop_context");
 #ifndef DBUG_OFF
-    Name_resolution_context *context= context_stack.pop();
+    Name_resolution_context *context=
+#endif
+    context_stack.pop();
+
     DBUG_PRINT("info", ("Pop context %p Select: %p (%d)",
                          context, context->select_lex,
                          (context->select_lex ?
                           context->select_lex->select_number:
                           0)));
-#endif
+
     DBUG_VOID_RETURN;
   }