cfg80211: free_priv for BSS info

When cfg80211 users have their own allocated data in the per-BSS
private data, they will need to free this when the BSS struct is
destroyed. Add a free_priv method and fix one place where the BSS
was kfree'd rather than released properly.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 09a0b26..b514abc 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -567,6 +567,7 @@
  * @len_information_elements: total length of the information elements
  * @signal: signal strength value
  * @signal_type: signal type
+ * @free_priv: function pointer to free private data
  * @priv: private area for driver use, has at least wiphy->bss_priv_size bytes
  */
 struct cfg80211_bss {
@@ -582,6 +583,7 @@
 	s32 signal;
 	enum cfg80211_signal_type signal_type;
 
+	void (*free_priv)(struct cfg80211_bss *bss);
 	u8 priv[0] __attribute__((__aligned__(sizeof(void *))));
 };