This option tells linker to look for local libraries first. If you have
a shared livavcodec/libavformat in the library path and try to build a
static build, the linker will find the shared library first and link
with it.
patch by (Roine Gustafsson <roine users.sourceforge net>)

Originally committed as revision 3793 to svn://svn.ffmpeg.org/ffmpeg/trunk