netiucv: remove unused macro

If someone is interested to dump something they may consider to use
print_hex_dump() or print_hex_dump_bytes() kernel helpers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>