iomap: don't increase i_size in iomap_write_end()

iomap: don't increase i_size in iomap_write_end()

This reverts commit '0841ea4a3b41 ("iomap: keep on increasing i_size in
iomap_write_end()")'.

After xfs could zero out the tail blocks aligned to the allocation
unitsize and convert the tail blocks to unwritten for realtime inode on
truncate down, it couldn't expose any stale data when unaligned truncate
down realtime inodes, so we could keep on keeping i_size for
IOMAP_UNSHARE and IOMAP_ZERO in iomap_write_end().

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240618142112.1315279-3-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>