isdn: accept CAPI Informational Info values as success

Info values in the 0x00xx range are defined in the CAPI standard
as "Informational, message processed successfully". Therefore a
CONNECT_B3_CONF message with an Info value in that range should
open an NCCI just as with Info==0.

Impact: minor bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Acked-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/capi/capi.c

@@ -603,7 +603,7 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 
 	if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_CONF) {
 		u16 info = CAPIMSG_U16(skb->data, 12); // Info field
-		if (info == 0) {
+		if ((info & 0xff00) == 0) {
 			mutex_lock(&cdev->ncci_list_mtx);
 			capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
 			mutex_unlock(&cdev->ncci_list_mtx);