[Linux] Fix mDNSResolver memory leak (#31709)

* [Linux] fix memory leak

* [Python] call StopDiscovery after DiscoveryNodes

---------

Co-authored-by: Andrei Litvin <andy314@gmail.com>

Author: tianfeng-yang

src/controller/python/ChipDeviceController-Discovery.cpp

@@ -89,6 +89,11 @@ PyChipError pychip_DeviceController_DiscoverCommissionableNodes(Controller::Devi
     return ToPyChipError(devCtrl->DiscoverCommissionableNodes(filter));
 }
 
+PyChipError pychip_DeviceController_StopCommissionableDiscovery(Controller::DeviceCommissioner * devCtrl)
+{
+    return ToPyChipError(devCtrl->StopCommissionableDiscovery());
+}
+
 void pychip_DeviceController_IterateDiscoveredCommissionableNodes(Controller::DeviceCommissioner * devCtrl,
                                                                   IterateDiscoveredCommissionableNodesFunct cb)
 {

src/controller/python/chip/ChipDeviceCtrl.py

@@ -594,6 +594,9 @@ def DiscoverCommissionableNodes(self, filterType: discovery.FilterType = discove
             else:
                 time.sleep(timeoutSecond)
 
+        self._ChipStack.Call(
+            lambda: self._dmLib.pychip_DeviceController_StopCommissionableDiscovery(self.devCtrl)).raise_on_error()
+
         return self.GetDiscoveredDevices()
 
     def DiscoverCommissionableNodesLongDiscriminator(self, long_discriminator):
@@ -1567,6 +1570,10 @@ def _InitLib(self):
                 c_void_p, c_uint8, c_char_p]
             self._dmLib.pychip_DeviceController_DiscoverCommissionableNodes.restype = PyChipError
 
+            self._dmLib.pychip_DeviceController_StopCommissionableDiscovery.argtypes = [
+                c_void_p]
+            self._dmLib.pychip_DeviceController_StopCommissionableDiscovery.restype = PyChipError
+
             self._dmLib.pychip_DeviceController_DiscoverCommissionableNodesLongDiscriminator.argtypes = [
                 c_void_p, c_uint16]
             self._dmLib.pychip_DeviceController_DiscoverCommissionableNodesLongDiscriminator.restype = PyChipError

src/platform/Linux/DnssdImpl.cpp

@@ -893,7 +893,7 @@ void MdnsAvahi::HandleResolve(AvahiServiceResolver * resolver, AvahiIfIndex inte
             avahi_service_resolver_free(resolver);
             context->mResolver = avahi_service_resolver_new(
                 context->mInstance->mClient, context->mInterface, context->mTransport, context->mName, context->mFullType.c_str(),
-                nullptr, context->mAddressType, static_cast<AvahiLookupFlags>(0), HandleResolve, context);
+                nullptr, context->mAddressType, static_cast<AvahiLookupFlags>(0), HandleResolve, userdata);
             if (context->mResolver == nullptr)
             {
                 ChipLogError(DeviceLayer, "Avahi resolve failed on retry");