lavfi/avcodec: fix typo

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/avcodec.c

@@ -100,7 +100,7 @@ AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_frame(const AVFrame *frame
         return NULL;
 
     if (layout && av_get_channel_layout_nb_channels(layout) != av_frame_get_channels(frame)) {
-        av_log(0, AV_LOG_ERROR, "Layout indicates a differnt number of channels than actually present\n");
+        av_log(0, AV_LOG_ERROR, "Layout indicates a different number of channels than actually present\n");
         return NULL;
     }