powerpc/pseries: replace kmalloc with kzalloc in PLPKS driver

[ Upstream commit 212dd5cf ]

Replace kmalloc with kzalloc in construct_auth() function to default
initialize structure with zeroes.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221106205839.600442-6-nayna@linux.ibm.com


Stable-dep-of: 78435434 ("powerpc/pseries: make max polling consistent for longer H_CALLs")
Signed-off-by: Sasha Levin <sashal@kernel.org>