Use %*ph format to print small buffer as hex string.

Link: https://lore.kernel.org/r/20200730153535.39691-1-andriy.shevchenko@linux.intel.comSigned-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>