general.texi: use "the FFmpeg libraries" in place of enumerating them

Avoid an incomplete listing of the libav* libraries, and the need to
update them again.

doc/general.texi

@@ -854,7 +854,7 @@ where SDL was installed. Verify that @file{sdl-config} can be launched from
 the MSYS command line.
 
 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
-you can build libavutil, libavcodec and libavformat as DLLs.
+you can build the FFmpeg libraries as DLLs.
 
 @end itemize