tests: Improve ABI_UPDATE macros

tests: Improve ABI_UPDATE macros

There are a number of cases in which we want to test both the
normal behavior and the ABI_UPDATE behavior for the same input
XML.

The way this is currently implemented is ad-hoc, and involves
symlinking the input XML as well as coming up with an
alternative name for the ABI_UPDATE variant: in most cases the
-abi-update suffix is added, but since this is not enforced
there are a couple of cases where we do something else instead.

To make things simpler and more consistent, implement the
naming convention at the macro level. This way, we no longer
need to create any symlinks for the input file, and the output
files are automatically named correctly.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>