Merge pull request autotest#4259 from xiagao/bz3377-balloon-stress

balloon_stress: update cmd_output_safe() with cmd_output()

Author: YongxueHong

qemu/tests/balloon_stress.py

@@ -28,7 +28,7 @@ def check_bg_running():
         """
         if params["os_type"] == "windows":
             list_cmd = params.get("list_cmd", "wmic process get name")
-            output = session.cmd_output_safe(list_cmd, timeout=60)
+            output = session.cmd_output(list_cmd, timeout=60)
             process = re.findall("mplayer", output, re.M | re.I)
             return bool(process)
         else: