qla3xxx: bugfix for line omitted in previous patch.

This missing line caused transmit errors on the Qlogic 4032 chip.

Signed-off-by: Ron Mercer <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/qla3xxx.c

···
 {
 	struct oal *oal;
 	struct oal_entry *oal_entry;
-	int len = skb->len;
+	int len = skb_headlen(skb);
 	dma_addr_t map;
 	int err;
 	int completed_segs, i;