[git pull] more ->lookup() cleanups

[Al Viro]

	Some ->lookup() instances are still overcomplicating the life
for themselves, open-coding the stuff that would be handled by
d_splice_alias() just fine.  Simplify a couple of such cases caught
this cycle and document d_splice_alias() intended use.

The following changes since commit 5b394b2ddf0347bef56e50c69a58773c94343ff3:

  Linux 4.19-rc1 (2018-08-26 14:11:59 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git work.lookup

for you to fetch changes up to 1a16dbaf798c5b68ac767444eb045e6f3adaa16d:

  Document d_splice_alias() calling conventions for ->lookup() users. (2018-10-10 16:52:37 -0400)

----------------------------------------------------------------
Al Viro (3):
      clean erofs_lookup()
      simplify btrfs_lookup()
      Document d_splice_alias() calling conventions for ->lookup() users.

 Documentation/filesystems/porting | 11 +++++++++++
 drivers/staging/erofs/namei.c     | 19 +++++++------------
 fs/btrfs/inode.c                  | 12 +++---------
 3 files changed, 21 insertions(+), 21 deletions(-)