mac80211: simplify key locking

Since I recently made station management able
to sleep, I can now rework key management as
well; since it will no longer need a spinlock
and can also use a mutex instead, a bunch of
code to allow drivers' set_key to sleep while
key management is protected by a spinlock can
now be removed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 47d6753..4d3883e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -746,10 +746,10 @@
 	struct mutex iflist_mtx;
 
 	/*
-	 * Key lock, protects sdata's key_list and sta_info's
+	 * Key mutex, protects sdata's key_list and sta_info's
 	 * key pointers (write access, they're RCU.)
 	 */
-	spinlock_t key_lock;
+	struct mutex key_mtx;
 
 
 	/* Scanning and BSS list */