xfs: Specify lockmode when calling xfs_ilock_for_iomap()

This patch changes the helper function xfs_ilock_for_iomap such that the
lock mode must be passed in.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-14-shr@fb.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>