Dont require /home/chrome-bot

R=navabi@chromium.org
NOTRY=true
BUG=460630

Review URL: https://codereview.chromium.org/946733002

Cr-Commit-Position: refs/heads/master@{#317448}

build/android/buildbot/bb_device_status_check.py

@@ -337,11 +337,12 @@ def main():
         zip(*[DeviceInfo(dev, options) for dev in devices]))
 
   # Write device info to file for buildbot info display.
-  with open('/home/chrome-bot/.adb_device_info', 'w') as f:
-    for device in json_data:
-      f.write('%s %s %s %.1fC %s%%\n' % (device['serial'], device['type'],
-          device['build'], float(device['battery']['temperature']) / 10,
-          device['battery']['level']))
+  if os.path.exists('/home/chrome-bot'):
+    with open('/home/chrome-bot/.adb_device_info', 'w') as f:
+      for device in json_data:
+        f.write('%s %s %s %.1fC %s%%\n' % (device['serial'], device['type'],
+            device['build'], float(device['battery']['temperature']) / 10,
+            device['battery']['level']))
 
   err_msg = CheckForMissingDevices(options, devices) or []