Staging: unisys: Replace kmalloc/memset with kzalloc

This patch solves the Coccinelle warning: "kzalloc should be used instead of
kmalloc/memset".

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>