Simplify code of issuing RMA packets.
When issuing RMA packets, we do not need to store target_win_handle in the request on origin side but only need to store source_win_handle. Because when the response data is back, we only needs to use source_win_handle on origin size. This patch simplifies the code in this way. Signed-off-by: Pavan Balaji <email@example.com>