Search the install library path as well as the hard coded /usr/lib
and /usr/local/lib (this is particularly important on system that
use the 64 suffix on x86_64.
(cherry picked from commit 47ffd252b036e4047054e3926ba0a9f94170c35e)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>