mac80211: remove the dependency on crypto_blkcipher

The only thing that using crypto_blkcipher with ecb does over just using
arc4 directly is wrapping the encrypt/decrypt function into a for loop,
looping over each individual character.
To be able to do this, it pulls in around 40 kb worth of unnecessary
kernel modules (at least on a MIPS embedded device).
Using arc4 directly not only eliminates those dependencies, it also makes
the code smaller.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index a404017..6eb2c852 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -809,8 +809,8 @@
 
 	struct rate_control_ref *rate_ctrl;
 
-	struct crypto_blkcipher *wep_tx_tfm;
-	struct crypto_blkcipher *wep_rx_tfm;
+	struct crypto_cipher *wep_tx_tfm;
+	struct crypto_cipher *wep_rx_tfm;
 	u32 wep_iv;
 
 	/* see iface.c */