Jenkins pr-builder.sh: Add "--bind-to none"

Similar to
open-mpi/ompi-scripts@7dc912e,
add "--bind-to none" to the mpirun command.

The CI tests on the AWS jenkins instance all run on instances with 1
core.  There's a special case in OMPI to bind to core for a 2 process
run for benchmarking reasons, and this was causing failures in mapping
because there aren't 2 cores on the instance.  So instead turn off
binding for these small tests.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

Author: jsquyres

.ci/community-jenkins/pr-builder.sh

@@ -299,7 +299,7 @@ if test "${MPIRUN_MODE}" != "none"; then
             exec="timeout -s SIGSEGV 3m mpirun -hostfile ${WORKSPACE}/hostfile -np 2 "
             ;;
         *)
-            exec="timeout -s SIGSEGV 4m mpirun --get-stack-traces --timeout 180 --hostfile ${WORKSPACE}/hostfile -np 2 "
+            exec="timeout -s SIGSEGV 4m mpirun --get-stack-traces --timeout 180 --hostfile ${WORKSPACE}/hostfile -np 2 --bind-to none "
             ;;
     esac
     singleton="timeout -s SIGSEGV 1m "