minor sk(4) patch

[Michal Belczyk]

The attached patch prevents the driver from reinitializing card when it's
already running.. basically useful when adding multiple interface aliases,
because it takes much less time :-)
Obtained from OpenBSD.

-- 
Michal Belczyk
Index: if_sk.c
===================================================================
RCS file: /home/dcvs/src/sys/dev/netif/sk/if_sk.c,v
retrieving revision 1.41.2.1
diff -u -r1.41.2.1 if_sk.c
--- if_sk.c	1 Jan 2006 00:59:05 -0000	1.41.2.1
+++ if_sk.c	13 Mar 2006 18:11:17 -0000
@@ -1025,6 +1025,7 @@
 			error = EINVAL;
 		else {
 			ifp->if_mtu = ifr->ifr_mtu;
+			ifp->if_flags &= ~IFF_RUNNING;
 			sk_init(sc_if);
 		}
 		break;
@@ -1672,6 +1673,7 @@
 	sc_if = ifp->if_softc;
 
 	printf("sk%d: watchdog timeout\n", sc_if->sk_unit);
+	ifp->if_flags &= ~IFF_RUNNING;
 	sk_init(sc_if);
 
 	if (!ifq_is_empty(&ifp->if_snd))
@@ -2274,6 +2276,11 @@
 
 	crit_enter();
 
+	if (ifp->if_flags & IFF_RUNNING) {
+		crit_exit();
+		return;
+	}
+
 	/* Cancel pending I/O and free all RX/TX buffers. */
 	sk_stop(sc_if);