Fix panic in the tap driver when a tap and vmnet interface were

created after each other e.g.

 ifconfig tap0
 ifconfig vmnet0
 <panic>

Appears to be a cut'n'paste error from the tap code to the vmnet
code where the name string wasn't updated in the call to make_dev().

Reviewed by:	glebius
MFC after:	3 days

sys/net/if_tap.c

@@ -205,7 +205,7 @@ vmnet_clone_create(struct if_clone *ifc, int unit, caddr_t params)
 	i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, VMNET_DEV_MASK);
 	if (i) {
 		dev = make_dev(&tap_cdevsw, unit | VMNET_DEV_MASK, UID_ROOT,
-		    GID_WHEEL, 0600, "%s%d", tapname, unit);
+		    GID_WHEEL, 0600, "%s%d", vmnetname, unit);
 	}
 
 	tapcreate(dev);