vmx2xmltest: Drop custom file name parse function

vmx2xmltest: Drop custom file name parse function

Having a custom file name parsing function in vmx2xml that's
different to the one used in production (esxParseVMXFileName())
might have served us well, but it also defeats the point of
having a unit test. More specifically, if there's a bug in
esxParseVMXFileName() then our unit test would not catch it.

But now that we have vmx2xmlmock the custom parsing function can
be dropped and the test can use the real one.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>