Problem: mysql_next_result_nonblocking() when called without any resultsets
is expected to return NET_ASYNC_COMPLETE_WITH_MORE_RESULTS which is a misleading
term.

Fix: Rename NET_ASYNC_COMPLETE_WITH_MORE_RESULTS to
NET_ASYNC_COMPLETE_NO_MORE_RESULTS

RB:21740
Reviewed-by:  <georgi.kodinov@oracle.com>