[media] staging: lirc: use %*ph to print small buffers

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>