vmx2xmltest: Deduplicate DO_TEST*() arguments

vmx2xmltest: Deduplicate DO_TEST*() arguments

In majority of DO_TEST() and DO_TEST_FAIL() calls the input vmx
file name is the same as the output XML file. Therefore, it's not
necessary to provide the same string twice. For the rest, where
the output XML file is different we can use symlinks to the
expected output.

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