Update run-phoenix-release-gpu.sh

Author: sbryngelson

misc/run-phoenix-release-gpu.sh

@@ -19,6 +19,6 @@ set -x
 gpu_count=$(nvidia-smi -L | wc -l)        # number of GPUs on node
 gpu_ids=$(seq -s ' ' 0 $(($gpu_count-1))) # 0,1,2,...,gpu_count-1
 
-./mfc.sh test -a -b mpirun -j $(nproc) \
+./mfc.sh test -a -b mpirun -j 1 \
               --gpu -g $gpu_ids