s390/zcrypt: fix kmalloc 256k failure

Tests showed that under stress conditions the kernel may
temporary fail to allocate 256k with kmalloc. However,
this fix reworks the related code in the cca_findcard2()
function to use kvmalloc instead.

Signed-off-by: Harald Freudenberger <[e-mail]>
Reviewed-by: Ingo Franzki <[e-mail]>
Cc: Stable <[e-mail]>
Signed-off-by: Vasily Gorbik <[e-mail]>

drivers/s390/crypto/zcrypt_ccamisc.c

···
 	*nr_apqns = 0;
 
 	/* fetch status of all crypto cards */
-	device_status = kmalloc_array(MAX_ZDEV_ENTRIES_EXT,
-				      sizeof(struct zcrypt_device_status_ext),
-				      GFP_KERNEL);
+	device_status = kvmalloc_array(MAX_ZDEV_ENTRIES_EXT,
+				       sizeof(struct zcrypt_device_status_ext),
+				       GFP_KERNEL);
 	if (!device_status)
 		return -ENOMEM;
 	zcrypt_device_status_mask_ext(device_status);
···
 		verify = 0;
 	}
 
-	kfree(device_status);
+	kvfree(device_status);
 	return rc;
 }
 EXPORT_SYMBOL(cca_findcard2);