filter/hdcd: include cleanup

src/filter/plugins/FfmpegFilter.cxx

@@ -26,6 +26,8 @@ extern "C" {
 #include <libavfilter/buffersink.h>
 }
 
+#include <string.h>
+
 FfmpegFilter::FfmpegFilter(const AudioFormat &in_audio_format,
 			   const AudioFormat &_out_audio_format,
 			   Ffmpeg::FilterGraph &&_graph,

src/filter/plugins/HdcdFilterPlugin.cxx

@@ -24,13 +24,8 @@
 #include "filter/NullFilter.hxx"
 #include "filter/Prepared.hxx"
 #include "lib/ffmpeg/Filter.hxx"
-#include "lib/ffmpeg/Frame.hxx"
-#include "lib/ffmpeg/SampleFormat.hxx"
-#include "config/Block.hxx"
 #include "AudioFormat.hxx"
 
-#include <string.h>
-
 static constexpr const char *hdcd_graph = "hdcd";
 
 gcc_pure