Call check_phase after UVM_FATAL

In reply to apinchev:

UVM_FATAL should be reserved for unrecoverable errors where it makes no sense to continue and no data is to be trusted.

Normally simulation continues on a UVM_ERROR, but you can make the test end by killing all you sequences, or dropping all objections in a report catcher. What method you use would use to abruptly end your test might depend on the method you normally use to end the test.