jbd2: drop useless return value of submit_bh

submit_bh always returns 0. This patch cleans up 2 of it's caller
in jbd2 to drop submit_bh's useless return value.
Once all submit_bh callers are cleaned up, we can make it's return
type as void.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/e069c0539be0aec61abcdc6f6141982ec85d489d.1660788334.git.ritesh.list@gmail.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>