media: ivtvfb: Cleanup some warnings

drivers/media/pci/ivtv/ivtvfb.c:349 ivtvfb_prep_frame() warn: argument 3 to %08lx specifier is cast from pointer
drivers/media/pci/ivtv/ivtvfb.c:360 ivtvfb_prep_frame() warn: argument 3 to %08lx specifier is cast from pointer
drivers/media/pci/ivtv/ivtvfb.c:363 ivtvfb_prep_frame() warn: argument 4 to %08lx specifier is cast from pointer

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>