Add an accessor for the proc_endpoints[OMPI_PROC_ENDPOINT_TAG_MTL]
member of the ompi_proc_t structure. This accessort calls add_procs
with the ompi_proc_t if the member is NULL. Tested on an infinipath
system with InfiniPath_QLE7340 HCAs.
Signed-off-by: Nathan Hjelm <hjelmn@me.com>