test: empty expected_absent capabilities check
test: empty expected_absent capabilities check

The 'simc://' and 'sim://' plugins are not sharing the same list of
UNSUPPORTED capabilities.

Before sync the behaviour of these two plugins, I would like to make test pass
by empty expected_absent capabilities check

Signed-off-by: Gris Ge <e24f3acbe39bf94f92e8af3c48f8852106ad5ad7@redhat.com>

jumitche/libstoragemgmt,tasleson/libstoragemgmt,libstorage/libstoragemgmt,joehandzik/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,jumitche/libstoragemgmt,cathay4t/libstoragemgmt,cathay4t/libstoragemgmt,tasleson/libstoragemgmt,tasleson/libstoragemgmt,joehandzik/libstoragemgmt,lazy404/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,cathay4t/libstoragemgmt,cathay4t/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,libstorage/libstoragemgmt,jumitche/libstoragemgmt,joehandzik/libstoragemgmt,jumitche/libstoragemgmt,joehandzik/libstoragemgmt,tasleson/libstoragemgmt,lazy404/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,libstorage/libstoragemgmt,cathay4t/libstoragemgmt,libstorage/libstoragemgmt,lazy404/libstoragemgmt,jumitche/libstoragemgmt,tasleson/libstoragemgmt,lazy404/libstoragemgmt,libstorage/libstoragemgmt