ntb_transport: Remove unnecessary call to ntb_peer_spad_read

The results were previously ignored, anyway.

Signed-off-by: Steve Wahl <Steve.Wahl@dell.com>
Fixes: e26a5843
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>