This consistency check was originally added by commit 9287c645
("gfs2: Fix occasional glock use-after-free").  It is ill-placed in
gfs2_glock_free() because if it holds there, it must equally hold in
__gfs2_glock_put() already.  Either way, the check doesn't seem
necessary anymore.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>