fs/buffer: drop useless return value of submit_bh

submit_bh always returns 0. This patch drops the useless return value of
submit_bh from __sync_dirty_buffer(). Once all of submit_bh callers are
cleaned up, we can make it's return type as void.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a98a6ddfac68f73d684c2724952e825bc1f4d238.1660788334.git.ritesh.list@gmail.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/buffer.c

@@ -2801,8 +2801,6 @@ EXPORT_SYMBOL(write_dirty_buffer);
  */
 int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 {
-	int ret = 0;
-
 	WARN_ON(atomic_read(&bh->b_count) < 1);
 	lock_buffer(bh);
 	if (test_clear_buffer_dirty(bh)) {
@@ -2817,14 +2815,14 @@ int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(REQ_OP_WRITE | op_flags, bh);
+		submit_bh(REQ_OP_WRITE | op_flags, bh);
 		wait_on_buffer(bh);
-		if (!ret && !buffer_uptodate(bh))
-			ret = -EIO;
+		if (!buffer_uptodate(bh))
+			return -EIO;
 	} else {
 		unlock_buffer(bh);
 	}
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(__sync_dirty_buffer);