ALSA: hwdep: silence integer overflow warning

Smatch complains that if device is INT_MAX then device + 1 can
overflow.  It just means we would have an annoying loop while we
check all the devices from -2147483648 to SNDRV_MINOR_HWDEPS.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>