avfilter/lavfutils: fix memleak of avpacket

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

libavfilter/lavfutils.c

@@ -33,6 +33,8 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     int frame_decoded, ret = 0;
     AVPacket pkt;
 
+    av_init_packet(&pkt);
+
     av_register_all();
 
     iformat = av_find_input_format("image2");
@@ -85,6 +87,7 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, *pix_fmt, *w, *h);
 
 end:
+    av_free_packet(&pkt);
     avcodec_close(codec_ctx);
     avformat_close_input(&format_ctx);
     av_freep(&frame);