Process the last video frame

On H.264 stream EOF, the eof_reached flag is set, but av_read_frame()
still provides a frame, so check the flag only afterwards.

As a side-effect, it also fixes a memory leak (the very last packet was
not unref).

app/src/decoder.c

@@ -92,10 +92,6 @@ static int run_decoder(void *data) {
     packet.size = 0;
 
     while (!av_read_frame(format_ctx, &packet)) {
-        if (avio_ctx->eof_reached) {
-            av_packet_unref(&packet);
-            goto run_quit;
-        }
 // the new decoding/encoding API has been introduced by:
 // <http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=7fc329e2dd6226dfecaa4a1d7adf353bf2773726>
 #if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 37, 0)
@@ -129,6 +125,10 @@ static int run_decoder(void *data) {
         }
 #endif
         av_packet_unref(&packet);
+
+        if (avio_ctx->eof_reached) {
+            break;
+        }
     }
 
     LOGD("End of frames");