mac80211: Add MIC space only for TX key option

Add a key flag to indicates that the device only needs
MIC space and not a real MIC.
In such cases, keep the MIC zeroed for ease of debug.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3160954..25904af 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2922,7 +2922,9 @@ void ieee80211_check_fast_xmit(struct sta_info *sta)
 
 		gen_iv = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV;
 		iv_spc = build.key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE;
-		mmic = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC;
+		mmic = build.key->conf.flags &
+			(IEEE80211_KEY_FLAG_GENERATE_MMIC |
+			 IEEE80211_KEY_FLAG_PUT_MIC_SPACE);
 
 		/* don't handle software crypto */
 		if (!(build.key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))