The testsuite is absolutely essential to feeling comfortable
about swapping the backing chain structure over to a new format.
This patch tests the path settings, and demonstrates that the
correct short name is being passed to the child.

* tests/virstoragetest.c (testStorageChain): Test path.
(mymain): Update expected data.
Signed-off-by: NEric Blake <eblake@redhat.com>