iwlwifi: mvm: clean up invalid station handling

Using IWL_MVM_STATION_COUNT and IWL_INVALID_STATION together
isn't a good idea as they have different values. Always use
IWL_MVM_STATION_COUNT for an invalid station in MVM and move
the definition of the IWL_INVALID_STATION constant into the
DVM driver to avoid making such mistakes again. The one use
in the transport code can be hard-coded to -1 instead as the
station ID is passed as an integer there.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 7f9c254..7a13790 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -305,7 +305,6 @@
  * currently supports
  */
 #define IWL_MAX_HW_QUEUES		32
-#define IWL_INVALID_STATION	255
 #define IWL_MAX_TID_COUNT	8
 #define IWL_FRAME_LIMIT	64
 
@@ -682,7 +681,7 @@
 static inline void iwl_trans_ac_txq_enable(struct iwl_trans *trans, int queue,
 					   int fifo)
 {
-	iwl_trans_txq_enable(trans, queue, fifo, IWL_INVALID_STATION,
+	iwl_trans_txq_enable(trans, queue, fifo, -1,
 			     IWL_MAX_TID_COUNT, IWL_FRAME_LIMIT, 0);
 }