media: cx25821-alsa: number of pages should be unsigned long

As reported by smatch:

	drivers/media/pci/cx25821/cx25821-alsa.c:146 cx25821_alsa_dma_init() warn: should 'nr_pages << 12' be a 64 bit type?

the number of patches should be unsigned long.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
1 file changed