gfs2: Use mod_delayed_work in gfs2_queue_try_to_evict

In the unlikely case that we're trying to queue GLF_TRY_TO_EVICT work
for an inode that already has GLF_VERIFY_DELETE work queued, we want to
make sure that the GLF_TRY_TO_EVICT work gets scheduled immediately
instead of waiting for the delayed work timer to expire.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>