Remove code duplication, let the mapping function hand us the actual button
event to be passed up to the server.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
We don't really do anything with the number other than print it since I'm sure
that half the mice don't report the correct number anyway (especially with the
wheel button mapping). But having a bit more debug info is good.
