Perl test script:  Avoid some aborts, which made the whole build/test process terminate.
Perl test script:  Avoid some aborts, which made the whole build/test process terminate.


mysql-test/lib/mtr_process.pl:
  Change from "mtr_error()" to "mtr_warning()" on some problems,
  because "error" makes the whole suite abort which then makes "Do-compile" terminate,
  so none of the following steps (including other etst suites) will be done.

ollie314/server,ollie314/server,natsys/mariadb_10.2,ollie314/server,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,slanterns/server,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,ollie314/server