setdar: prefer "sar" over "par" in log info message

This is more consistent with the terminology adopted by the aspect
filter names.

libavfilter/vf_aspect.c

@@ -80,7 +80,7 @@ static int setdar_config_props(AVFilterLink *inlink)
                aspect->aspect.num * inlink->h,
                aspect->aspect.den * inlink->w, 100);
 
-    av_log(inlink->dst, AV_LOG_INFO, "w:%d h:%d -> dar:%d/%d par:%d/%d\n",
+    av_log(inlink->dst, AV_LOG_INFO, "w:%d h:%d -> dar:%d/%d sar:%d/%d\n",
            inlink->w, inlink->h, dar.num, dar.den, aspect->aspect.num, aspect->aspect.den);
 
     inlink->sample_aspect_ratio = aspect->aspect;