qemu.tests: Update netperf_stress config in suspend_under_netperf test case.

Need update netperf_stress config after netperf_stress.py updated.

Signed-off-by: Feng Yang <fyang@redhat.com>
Merge pull request #131 from FengYang/vm_arch_name

qemu.tests: Update netperf_stress config in suspend_under_netperf test case.