mac80211: free up 2 bytes in skb->cb

Free up 2 bytes in skb->cb to be used for multi-rate retry later.
Move iv_len and icv_len initialization into key alloc.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 5e0b71c..e0749c0 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -252,7 +252,7 @@
 		}
 
 		/* Hardware appends ICV. */
-		plcp_fragment_len += info->control.icv_len;
+		plcp_fragment_len += info->control.hw_key->icv_len;
 
 		key_idx = b43_kidx_to_fw(dev, key_idx);
 		mac_ctl |= (key_idx << B43_TXH_MAC_KEYIDX_SHIFT) &
@@ -260,7 +260,7 @@
 		mac_ctl |= (key->algorithm << B43_TXH_MAC_KEYALG_SHIFT) &
 			   B43_TXH_MAC_KEYALG;
 		wlhdr_len = ieee80211_hdrlen(fctl);
-		iv_len = min((size_t) info->control.iv_len,
+		iv_len = min((size_t) info->control.hw_key->iv_len,
 			     ARRAY_SIZE(txhdr->iv));
 		memcpy(txhdr->iv, ((u8 *) wlhdr) + wlhdr_len, iv_len);
 	}