avfilter/buffer: Suppress deprecation warning for avfilter_unref_buffer

The function is used in a block of code that is deprecated anyway.

libavfilter/buffer.c

@@ -18,6 +18,7 @@
 
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
+#include "libavutil/internal.h"
 #include "libavcodec/avcodec.h"
 
 #include "avfilter.h"
@@ -89,7 +90,9 @@ void avfilter_unref_buffer(AVFilterBufferRef *ref)
 
 void avfilter_unref_bufferp(AVFilterBufferRef **ref)
 {
+FF_DISABLE_DEPRECATION_WARNINGS
     avfilter_unref_buffer(*ref);
+FF_ENABLE_DEPRECATION_WARNINGS
     *ref = NULL;
 }