mac80211: add might_sleep to hw_config

Just to catch bugs when changing mac80211.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/main.c

@@ -203,6 +203,8 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 	int ret = 0;
 	int power;
 
+	might_sleep();
+
 	if (local->sw_scanning)
 		chan = local->scan_channel;
 	else