UPSTREAM: fs: make do_renameat2() take struct filename

[ Upstream commit e886663c ]

Pass in the struct filename pointers instead of the user string, and
update the three callers to do the same.

This behaves like do_unlinkat(), which also takes a filename struct and
puts it when it is done. Converting callers is then trivial.

Change-Id: Ie23f87f8c6bb18a61254a0848d861ad6fad14232
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 214f80e2)
Bug: 268174392
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>