isdn: mISDN: set ->family in ->getname()

The "maddr->family" variable was not set but instead it leaked stack
information to userspace.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index 8b07f83..e47dcb9 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -578,6 +578,7 @@
 	lock_sock(sk);
 
 	*addr_len = sizeof(*maddr);
+	maddr->family = AF_ISDN;
 	maddr->dev = _pms(sk)->dev->id;
 	maddr->channel = _pms(sk)->ch.nr;
 	maddr->sapi = _pms(sk)->ch.addr & 0xff;