libobs: Fix bug rendering async video with filters

This code was originally meant to skip some checks as an optimization,
but it did not account for async video sources and would call
obs_source_default_render (which is only for synchronous video sources),
this fixes the issue by just calling obs_source_video_render.

libobs/obs-source.c

@@ -2026,10 +2026,7 @@ void obs_source_process_filter(obs_source_t *filter, gs_effect_t *effect,
 
 	if (gs_texrender_begin(filter->filter_texrender, cx, cy)) {
 		gs_ortho(0.0f, (float)cx, 0.0f, (float)cy, -100.0f, 100.0f);
-		if (expects_def && parent == target)
-			obs_source_default_render(parent, use_matrix);
-		else
-			obs_source_video_render(target);
+		obs_source_video_render(target);
 		gs_texrender_end(filter->filter_texrender);
 	}