cfg80211: constify more pointers in the cfg80211 API

This also propagates through the drivers.

The orinoco driver uses the cfg80211 API structs for internal
bookkeeping, and so needs a (void *) cast that removes the
const - but that's OK because it allocates those pointers.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index 6b50588..8f345da 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -420,8 +420,8 @@
 	if (len > 0 && ssid[len - 1] == '\0')
 		len--;
 
+	memcpy(wdev->ssid, ssid, len);
 	wdev->wext.ibss.ssid = wdev->ssid;
-	memcpy(wdev->wext.ibss.ssid, ssid, len);
 	wdev->wext.ibss.ssid_len = len;
 
 	wdev_lock(wdev);