avcodec/qdmc: Mark decoder as init-threadsafe

It already uses ff_thread_once() to initialize its static data.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavcodec/qdmc.c

@@ -736,4 +736,5 @@ AVCodec ff_qdmc_decoder = {
     .decode           = qdmc_decode_frame,
     .flush            = qdmc_flush,
     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
+    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE,
 };