libx264: unbreak libx264rgb

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libx264.c

@@ -655,7 +655,7 @@ AVCodec ff_libx264rgb_encoder = {
     .id             = CODEC_ID_H264,
     .priv_data_size = sizeof(X264Context),
     .init           = X264_init,
-    .encode         = X264_frame,
+    .encode2        = X264_frame,
     .close          = X264_close,
     .capabilities   = CODEC_CAP_DELAY,
     .long_name      = NULL_IF_CONFIG_SMALL("libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 RGB"),