dm-verity: remove unnecessary condition for verity_fec_finish_io()

dm-verity: remove unnecessary condition for verity_fec_finish_io()

Make verity_finish_io() call verity_fec_finish_io() unconditionally,
instead of skipping it when 'in_bh' is true.

Although FEC can't have been done when 'in_bh' is true,
verity_fec_finish_io() is a no-op when FEC wasn't done.  An earlier
change also made verity_fec_finish_io() very lightweight when FEC wasn't
done.  So it should just be called unconditionally.

Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>