Fix fsid bug in FSAL_VFS

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>
Fixup FSAL_GPFS lookup to work if run on older GPFS

Older GPFS doesn't pass back the fsid in the attributes. We need
to work around that condition.

Signed-off-by: Frank S. Filz <ffilzlnx@mindspring.com>