[S390] zcrypt: fix ap_reset_domain()

Resetting of a all queues within a domain requires that a domain must
be selected first.
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/crypto/ap_bus.c

@@ -1231,6 +1231,7 @@ static void ap_reset_domain(void)
 {
 	int i;
 
+	if (ap_domain_index != -1)
 		for (i = 0; i < AP_DEVICES; i++)
 			ap_reset_queue(AP_MKQID(i, ap_domain_index));
 }