s2io: set_multicast_list bug

The mac_addr variable doesn't get reset between
(re)additions of multicast addresses. One byte
of all multicast addresses (except the first)
can be incorrect.

Signed-off-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 49b597c..b7f00d6 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -4092,6 +4092,7 @@
 		     i++, mclist = mclist->next) {
 			memcpy(sp->usr_addrs[i].addr, mclist->dmi_addr,
 			       ETH_ALEN);
+			mac_addr = 0;
 			for (j = 0; j < ETH_ALEN; j++) {
 				mac_addr |= mclist->dmi_addr[j];
 				mac_addr <<= 8;