s390/zcrypt: Fix ZCRYPT_PERDEV_REQCNT ioctl

reqcnt is an u32 pointer but we do copy sizeof(reqcnt) which is the
size of the pointer. This means we only copy 8 byte. Let us copy
the full monty.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: af4a7227 ("s390/zcrypt: Support up to 256 crypto adapters.")
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

drivers/s390/crypto/zcrypt_api.c

@@ -1449,7 +1449,8 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
 		if (!reqcnt)
 			return -ENOMEM;
 		zcrypt_perdev_reqcnt(reqcnt, AP_DEVICES);
-		if (copy_to_user((int __user *) arg, reqcnt, sizeof(reqcnt)))
+		if (copy_to_user((int __user *) arg, reqcnt,
+				 sizeof(u32) * AP_DEVICES))
 			rc = -EFAULT;
 		kfree(reqcnt);
 		return rc;