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/net/mac80211/key.c b/net/mac80211/key.c
index 57afcd3..a5b06fe 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -281,6 +281,20 @@
 	key->conf.alg = alg;
 	key->conf.keyidx = idx;
 	key->conf.keylen = key_len;
+	switch (alg) {
+	case ALG_WEP:
+		key->conf.iv_len = WEP_IV_LEN;
+		key->conf.icv_len = WEP_ICV_LEN;
+		break;
+	case ALG_TKIP:
+		key->conf.iv_len = TKIP_IV_LEN;
+		key->conf.icv_len = TKIP_ICV_LEN;
+		break;
+	case ALG_CCMP:
+		key->conf.iv_len = CCMP_HDR_LEN;
+		key->conf.icv_len = CCMP_MIC_LEN;
+		break;
+	}
 	memcpy(key->conf.key, key_data, key_len);
 	INIT_LIST_HEAD(&key->list);
 	INIT_LIST_HEAD(&key->todo);