WL#2611: Add query length to mysql_query_with_error_report() in mysqldump.c

Affects: Server-7.1   —   Status: Un-Assigned   —   Priority: Medium

client/mysqldump.c could be optimized slightly by adding a length parameter to 
mysql_query_with_error_report(), so it could call mysql_real_query() instead of 
mysql_query().