test-rename-merge2: make selected output less arbitrary
It's unclear why everything from the first 'updating:' line should be
ignored. The arbitrariness makes it confusing that changing the code
so e.g. the 'getting 8/f' line is printed later makes it disappear
completely from the ouput. The list of 'preserving x for resolve of y'
seems convered by the subsequent for loop in the test case. Perhaps
it's only copies that are of interests, so let's keep only that part.