ALSA: isa/wavefront: prevent some out of bound writes

[ Upstream commit 84d7a4470dbac0dd9389050100b54a1625d04264 ]

"header->number" can be up to USHRT_MAX and it comes from the ioctl so
it needs to be capped.

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