complibs: better deduce whether to backup complibs or not

To decide whether we need to backup the companion libraries,
do not rely on the !shared case. In the future other cases
may require not to save the companion libraries (eg. if using
the ones provided by the host distro).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 This is NOT the official version of dialog.  This version has been

 significantly modified from the original.  It is for use by the Linux

 kernel configuration script.  Please do not bother Savio Lam with 

 questions about this program.