errors without code removed

net_printf/send_error calls replaced by my_error family functions
-1/1 (sent/unsent) error reporting removed
(WL#2133)

sql/sql_class.h

@@ -1112,6 +1112,7 @@ public:
     net.last_error[0]= 0;
     net.last_errno= 0;
     net.report_error= 0;
+    query_error= 0;
   }
   inline bool vio_ok() const { return net.vio != 0; }
 #else