LU-10531 obd: handle case tgt equals fsname for obdname2fsname

LU-10531 obd: handle case tgt equals fsname for obdname2fsname

The function obdname2fsname() was updated to handle the case of
when tgt was for the format:

llite.lustre*.xattr_cache
llite.lustre-*.xattr_cache

but the case of tgt being exactly equal to the fsname is also
valid as in the case of sptlrpc: fsname.srpc.flavor.default.cli2ost

Change-Id: I9bb4082ee5f194842c7d72ae25e14f6998c0b8ed
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/30937
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>