This was detected because events with invalid types were arriving
to userspace.

The code before this patch would only work for the first event in the
queue (when uhid->tail is 0).
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Reviewed-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>