mac80211: refactor ieee80211_ibss_process_chanswitch()

Refactor ieee80211_ibss_process_chanswitch() to use
ieee80211_channel_switch() and avoid code duplication.

Tested by: Simon Wunderlich <sw@simonwunderlich.de>
Acked by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index df32df3..35bb71b 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3038,8 +3038,8 @@
 	sdata_unlock(sdata);
 }
 
-static int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
-				    struct cfg80211_csa_settings *params)
+int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
+			     struct cfg80211_csa_settings *params)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_local *local = sdata->local;