qsvenc: mark the encoders as INIT_CLEANUP

Should fix some leaks on init failure.

libavcodec/qsvenc_h264.c

@@ -118,4 +118,5 @@ AVCodec ff_h264_qsv_encoder = {
                                                     AV_PIX_FMT_NONE },
     .priv_class     = &class,
     .defaults       = qsv_enc_defaults,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
 };

libavcodec/qsvenc_hevc.c

@@ -269,4 +269,5 @@ AVCodec ff_hevc_qsv_encoder = {
                                                     AV_PIX_FMT_NONE },
     .priv_class     = &class,
     .defaults       = qsv_enc_defaults,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
 };

libavcodec/qsvenc_mpeg2.c

@@ -114,4 +114,5 @@ AVCodec ff_mpeg2_qsv_encoder = {
                                                     AV_PIX_FMT_NONE },
     .priv_class     = &class,
     .defaults       = qsv_enc_defaults,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
 };