Don't stop because we couldn't restart usb devices.

One of the build bots was failing to restart one device, but it still had four other devices online it could continue with.

BUG=

Review URL: https://codereview.chromium.org/59753003

git-svn-id: http://src.chromium.org/svn/trunk/src/build@243292 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/buildbot/bb_device_status_check.py

@@ -302,9 +302,11 @@ def main():
     # Only restart usb if devices are missing
     if set(expected_devices) != set(devices):
       KillAllAdb()
-      if RestartUsb():
-        return 1
       retries = 5
+      if RestartUsb():
+        bb_annotations.PrintWarning()
+        print "USB reset stage failed, continuing anyway."
+        retries = 0
       while retries:
         time.sleep(1)
         devices = android_commands.GetAttachedDevices()