avcodec/libopenh264enc: fix class_name

Reverts some accidental change in commit e621b1ca646a2f268797adc3194b694a852548d2.

Reviewed-by: Jan Ekström <[email protected]>
Signed-off-by: Tobias Rapp <[email protected]>
diff --git a/libavcodec/libopenh264enc.c b/libavcodec/libopenh264enc.c
index 5baa423..ae6d17c 100644
--- a/libavcodec/libopenh264enc.c
+++ b/libavcodec/libopenh264enc.c
@@ -75,7 +75,7 @@
 };
 
 static const AVClass class = {
-    .class_name = "libvo_amrwbenc",
+    .class_name = "libopenh264enc",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,