doxy: fix swr group name

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/avutil.h

@@ -39,7 +39,7 @@
  * @li @ref libavf "libavformat" I/O and muxing/demuxing library
  * @li @ref lavd "libavdevice" special devices muxing/demuxing library
  * @li @ref lavu "libavutil" common utility library
- * @li @ref libswresample "libswresample" audio resampling, format conversion and mixing
+ * @li @ref lswr "libswresample" audio resampling, format conversion and mixing
  * @li @subpage libpostproc post processing library
  * @li @subpage libswscale  color conversion and scaling library
  */

libswresample/swresample.h

@@ -23,6 +23,7 @@
 
 /**
  * @file
+ * @ingroup lswr
  * libswresample public header
  */