This commit fixes a bug that can occur when communicating via XRC to
peers on the same node. UDCM was not saving the SRQ numbers on the
loopback endpoint (which shares its ib_addr info with all local peers)
so any messages to local peers use an invalid SRQ number.
Fixesopen-mpi/ompi#1383
Signed-off-by: Nathan Hjelm <hjelmn@me.com>