There are two copies of list_sort() in the tree already, one in the DRM
code, another in ubifs. Now XFS needs this as well. Create a generic
list_sort() function from the ubifs version and convert existing users
to it so we don't end up with yet another copy in the tree.
Signed-off-by: Dave Chinner <david@fromorbit.com> Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Artem Bityutskiy <dedekind@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>