Sometimes, the ethernet interfaces can get quite high kernel indices. struct
ifreq (see netdevice(7)) defines ifr_ifindex to be int's. The OOB component
used int16_t internally for matching (in case of -mca oob_tcp_if_[in|ex]clude)
which meant that any interface index > 32767 would never be matched because the
integer would be truncated to int16_t upon return from the function. OOB would
then refuse to work because it didn't find any usable interfaces and MPI job
would abort.
Signed-off-by: Wojtek Wasko <wwasko@nvidia.com>