dontdiff: Fix asm exclude

Now that the headers are in arch/foo/include/asm we don't want to exclude
them when preparing diff files.

Closes-bug: 12921

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed