[ADVAPI32] Send correct type to ElfrChangeNotify()

This fixes the following compiler error:
../dll/win32/advapi32/service/eventlog.c:658:59: error: passing argument 3 of 'ElfrChangeNotify' makes integer from pointer without a cast [-Werror=int-conversion]
dll/win32/advapi32/eventlogrpc_c.h:391:20: note: expected 'ULONG {aka long unsigned int}' but argument is of type 'HANDLE {aka void *}'

dll/win32/advapi32/service/eventlog.c

···
 
     RpcTryExcept
     {
-        Status = ElfrChangeNotify(hEventLog, RpcClientId, (DWORD)hEvent);
+        Status = ElfrChangeNotify(hEventLog, RpcClientId, HandleToUlong(hEvent));
     }
     RpcExcept(EXCEPTION_EXECUTE_HANDLER)
     {