Fixed wrong packed length for packet > 16M.

sql/net_pkg.cc:
  Fixed wrong packed length for packet > 16M.
  (Not used in 3.23)

sql/net_pkg.cc

@@ -206,7 +206,7 @@ net_store_length(char *pkg, ulonglong length)
   }
   *packet++=254;
   int8store(packet,length);
-  return (char*) packet+9;
+  return (char*) packet+8;
 }
 
 char *