obs-qsv11: Migrate target usage settings

Calling update_targetusage in update_params only updates the setting
when an encoder session is initialized. Calling update_targetusage in
rate_control_modified, like update_latency and update_enhancements, will
update the setting when the Settings window is loaded. This will cause
the updated setting to be reflected in the UI.

plugins/obs-qsv11/obs-qsv11.c

@@ -403,6 +403,7 @@ static bool rate_control_modified(obs_properties_t *ppts, obs_property_t *p,
 
 	update_latency(settings);
 	update_enhancements(settings);
+	update_targetusage(settings);
 	update_ratecontrol(settings);
 
 	return true;