mpi_leave_pinned when multiple OpenIB HCA ports are found.
Specifically, if mpi_leave_pinned == 1 and ultiple HCA ports are
found, the MCA parameter btl_openib_max_btls is set to 1. If the MCA
parameter btl_openib_warn_leave_pinned_multi_port is true, emit a
warning that this happened (having an MCA parameter to control the
warning allows users/sysadmins to turn it off instead of being nagged
for every run).
This commit was SVN r10424.
