[usb-moded] Fix memory corruption issue

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Fix leak when setting the default mode configuration setting.

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Make sure the trigger does not get restarted when we clean up.

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Fix possible memory leak when setting the network config.

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>