validate: Fix error on GstTest.copy()
Fixes regression introduced in ba61160d, where running check tests with gst-validate-launcher -f would trigger this exception:
AttributeError: 'GstCheckTest' object has no attribute 'reports'.
Did you mean: 'reporter'?
The member reports
is meant to be just part of GstValidateTest, but not other subclasses, even though a usage is still found in the base class GstTest in the method test_end().
This patch introduces an override of the methods copy() and test_end() in GstValidateTest so that reports
is copied and cleared respectively, but only for validate tests.