ffmpeg_filter: use avcodec_find_best_pix_fmt_of_2()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg_filter.c

@@ -48,7 +48,7 @@ enum PixelFormat choose_pixel_fmt(AVStream *st, AVCodec *codec, enum PixelFormat
             }
         }
         for (; *p != PIX_FMT_NONE; p++) {
-            best= avcodec_find_best_pix_fmt2(best, *p, target, has_alpha, NULL);
+            best= avcodec_find_best_pix_fmt_of_2(best, *p, target, has_alpha, NULL);
             if (*p == target)
                 break;
         }