Fix 3 error handling issues:

1. In ov2680_s_stream(), when pm_runtime_get_sync() fails it will still
   have incremented the pm-runtime reference count so we need to call
   pm_runtime_put()

2. In ov2680_s_stream() sensor->is_streaming should always be set to false
   when the sensor is powered-off even on i2c-communication errors.

3. In ov2680_probe(), call ov2680_remove() on ov2680_s_config() errors,
   so that pm_runtime_disable() is properly called to disable the
   runtime-pm which has been enabled before the ov2680_s_config() call.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>