ffmpeg: Fix a typo in version detection

See f0b3e08e9c75e5cdcd98c0f3142469918d1d2fd5

panda/src/ffmpeg/ffmpegAudioCursor.cxx

@@ -143,7 +143,7 @@ FfmpegAudioCursor(FfmpegAudio *src) :
   _can_seek = true;
   _can_seek_fast = true;
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(54, 59, 100)
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(55, 45, 101)
   _frame = av_frame_alloc();
 #else
   _frame = avcodec_alloc_frame();

panda/src/ffmpeg/ffmpegVideoCursor.cxx

@@ -96,7 +96,7 @@ init_from(FfmpegVideo *source) {
 
   ReMutexHolder av_holder(_av_lock);
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(54, 59, 100)
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(55, 45, 101)
   _frame = av_frame_alloc();
   _frame_out = av_frame_alloc();
 #else