iwlwifi: mvm: Fix removal of IGTK

When removing an IGTK, iwl_mvm_send_sta_igtk() was
called before station ID was retrieved, so the function
was invoked with an invalid station ID. Fix this by first
getting the station ID.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=192411
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/sta.c

@@ -3047,6 +3047,11 @@ int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm,
 
 	/* Get the station from the mvm local station table */
 	mvm_sta = iwl_mvm_get_key_sta(mvm, vif, sta);
+	if (!mvm_sta) {
+		IWL_ERR(mvm, "Failed to find station\n");
+		return -EINVAL;
+	}
+	sta_id = mvm_sta->sta_id;
 
 	IWL_DEBUG_WEP(mvm, "mvm remove dynamic key: idx=%d sta=%d\n",
 		      keyconf->keyidx, sta_id);
@@ -3074,8 +3079,6 @@ int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm,
 		return 0;
 	}
 
-	sta_id = mvm_sta->sta_id;
-
 	ret = __iwl_mvm_remove_sta_key(mvm, sta_id, keyconf, mcast);
 	if (ret)
 		return ret;