s390/pkey: fix kzalloc-simple.cocci warnings

drivers/s390/crypto/pkey_api.c:128:11-18: WARNING:
kzalloc should be used for cprbmem, instead of kmalloc/memset

Use kzalloc rather than kmalloc followed by memset with 0
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/crypto/pkey_api.c

@@ -125,10 +125,9 @@ static int alloc_and_prep_cprbmem(size_t paramblen,
 	 * allocate consecutive memory for request CPRB, request param
 	 * block, reply CPRB and reply param block
 	 */
-	cprbmem = kmalloc(2 * cprbplusparamblen, GFP_KERNEL);
+	cprbmem = kzalloc(2 * cprbplusparamblen, GFP_KERNEL);
 	if (!cprbmem)
 		return -ENOMEM;
-	memset(cprbmem, 0, 2 * cprbplusparamblen);
 
 	preqcblk = (struct CPRBX *) cprbmem;
 	prepcblk = (struct CPRBX *) (cprbmem + cprbplusparamblen);