Adds an interface to the end of a list.
ADLX_RESULT Add_Back (IADLXDesktop * pItem)
[in]pItem IADLXDesktop* The pointer to the interface to be added to the list.
If the interface is added successfully to the end of the list, ADLX_OK is returned.
If the interface is not added to the end of the list, an error code is returned.
Refer to ADLX_RESULT for success codes and error codes.