mac80211: remove wep dependency

The current mac80211 code assumes that WEP is always available.  If WEP
fails to initialize, ieee80211_register_hw will always fail.

In some cases (e.g. FIPS certification), the cryptography used by WEP is
unavailable.  However, in such cases there is no good reason why CCMP
encryption (or even no link level encryption) cannot be used.  So, this
patch removes mac80211's assumption that WEP (and TKIP) will always be
available for use.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c
index 7ef491e..e840c9c 100644
--- a/net/mac80211/tkip.c
+++ b/net/mac80211/tkip.c
@@ -202,9 +202,9 @@
  * @payload_len is the length of payload (_not_ including IV/ICV length).
  * @ta is the transmitter addresses.
  */
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
-				 struct ieee80211_key *key,
-				 u8 *pos, size_t payload_len, u8 *ta)
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+				struct ieee80211_key *key,
+				u8 *pos, size_t payload_len, u8 *ta)
 {
 	u8 rc4key[16];
 	struct tkip_ctx *ctx = &key->u.tkip.tx;
@@ -216,7 +216,7 @@
 
 	tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key);
 
-	ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
+	return ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
 }
 
 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the