avfilter: remove duplicate and disabled trace log function

It's already defined and actually enabled depending on compiler options
elsewhere.
Signed-off-by: James Almer <jamrial@gmail.com>

libavfilter/internal.h

@@ -33,6 +33,7 @@
 #include "version.h"
 #include "video.h"
 #include "libavcodec/avcodec.h"
+#include "libavcodec/internal.h"
 
 typedef struct AVFilterCommand {
     double time;                ///< time expressed in seconds
@@ -246,14 +247,6 @@ void ff_command_queue_pop(AVFilterContext *filter);
 
 /* misc trace functions */
 
-/* #define FF_AVFILTER_TRACE */
-
-#ifdef FF_AVFILTER_TRACE
-#    define ff_tlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)
-#else
-#    define ff_tlog(pctx, ...) do { if (0) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
-#endif
-
 #define FF_TPRINTF_START(ctx, func) ff_tlog(NULL, "%-16s: ", #func)
 
 char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms);