avcodec/adpcmenc: don't share a single AVClass between multiple AVCodecs.

Temporary fix until AVClass::child_class_next is gone.

Reviewed-By: James Almer <jamrial@gmail.com>
Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
(cherry picked from commit aa1cfe05a5)

libavcodec/adpcmenc.c

@@ -959,14 +959,14 @@ static const AVOption options[] = {
     { NULL }
 };
 
-static const AVClass adpcm_encoder_class = {
-    .class_name = "ADPCM Encoder",
-    .item_name  = av_default_item_name,
-    .option     = options,
-    .version    = LIBAVUTIL_VERSION_INT,
-};
-
 #define ADPCM_ENCODER(id_, name_, sample_fmts_, capabilities_, long_name_) \
+static const AVClass name_ ## _encoder_class = {                           \
+    .class_name = #name_,                                                  \
+    .item_name  = av_default_item_name,                                    \
+    .option     = options,                                                 \
+    .version    = LIBAVUTIL_VERSION_INT,                                   \
+};                                                                         \
+                                                                           \
 AVCodec ff_ ## name_ ## _encoder = {                                       \
     .name           = #name_,                                              \
     .long_name      = NULL_IF_CONFIG_SMALL(long_name_),                    \
@@ -979,7 +979,7 @@ AVCodec ff_ ## name_ ## _encoder = {                                       \
     .sample_fmts    = sample_fmts_,                                        \
     .capabilities   = capabilities_,                                       \
     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE, \
-    .priv_class     = &adpcm_encoder_class,                                \
+    .priv_class     = &name_ ## _encoder_class,                            \
 }
 
 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_ARGO,    adpcm_argo,    sample_fmts_p, 0,                             "ADPCM Argonaut Games");