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/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index c0043fc..fe03160 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -940,7 +940,7 @@
 		 */
 		break;
 	case STA_NOTIFY_AWAKE:
-		if (WARN_ON(mvmsta->sta_id == IWL_INVALID_STATION))
+		if (WARN_ON(mvmsta->sta_id == IWL_MVM_STATION_COUNT))
 			break;
 		iwl_mvm_sta_modify_ps_wake(mvm, sta);
 		break;