net: systemport: use kcalloc instead of kzalloc

checkpatch.pl flagged two uses of kzalloc() for allocating and zeroing
arrays, use kcalloc() instead as recommended.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>