New MCA param: btl_usnic_max_resends_per_iteration. This is the max
number of resends we'll do in a single pass through usNIC component
progress. This prevents progress from getting stuck in an endless
loop of retransmissions (i.e., if more retransmissions are triggered
during the sending of retransmissions). Specifically: we need to
leave the resend loop to allow receives to happen (which may ACK
messages we have sent previously, and therefore cause pending resends
to be moot).
Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
(cherry picked from commit 27e3040dfeba00a9a2615a217c164899f0009e59)