Correctly set the library installation directory
Correctly set the library installation directory

Guessing the suffix to "lib" breaks down in cross-compilation
environments. Let's use the standard Cmake variable which can
be explicitly set from the build configuraion.

rpm-software-management/librepo,Tojaj/librepo,Tojaj/librepo,rpm-software-management/librepo,rpm-software-management/librepo,Tojaj/librepo