mac80211: refactor monitor representation in sdata

Insert the u32 monitor flags variable in a new structure
that represents a monitor interface.
This will allow to add more configuration variables to
that structure which will happen in an upcoming change.

Signed-off-by: Aviya Erenfeld <aviya.erenfeld@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 1d0746d..efc38e7 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1643,7 +1643,7 @@
 
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_MONITOR:
-		if (sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE) {
+		if (sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE) {
 			vif = &sdata->vif;
 			break;
 		}