[media] media/pci/cobalt: Use %*ph to print small buffers

printk() supports %*ph format specifier for printing a small buffers,
let's use it intead of %02x %02x...

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>