mac80211: remove support for IFF_PROMISC

This support is essentially useless as typically networks are encrypted,
frames will be filtered by hardware, and rate scaling will be done with
the intended recipient in mind. For real monitoring of the network, the
monitor mode support should be used instead.

Removing it removes a lot of corner cases.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index 5147ebe..14937cb 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.c
+++ b/drivers/net/wireless/ath/ar5523/ar5523.c
@@ -1319,8 +1319,7 @@
 
 }
 
-#define AR5523_SUPPORTED_FILTERS (FIF_PROMISC_IN_BSS | \
-				  FIF_ALLMULTI | \
+#define AR5523_SUPPORTED_FILTERS (FIF_ALLMULTI | \
 				  FIF_FCSFAIL | \
 				  FIF_OTHER_BSS)