avfilter/vf_ocr: check ff_set_common_formats() return value

Signed-off-by: Moritz Barsnick <barsnick@gmx.net>

libavfilter/vf_ocr.c

@@ -90,9 +90,7 @@ static int query_formats(AVFilterContext *ctx)
     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
-    ff_set_common_formats(ctx, fmts_list);
-
-    return 0;
+    return ff_set_common_formats(ctx, fmts_list);
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)