media: tuner-xc2028: don't use casts for printing sizes

Makes smatch happier by using %zd instead of casting sizes:
	drivers/media/tuners/tuner-xc2028.c:378 load_all_firmwares() warn: argument 4 to %d specifier is cast from pointer
	drivers/media/tuners/tuner-xc2028.c:619 load_firmware() warn: argument 6 to %d specifier is cast from pointer

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>