populate: fix installing dynamic linker 'ld.so'

The dynamic linker, ld.so, needs the execute bit to be set.
Detect tht the library being installed is in fact ld.so and
install it with 0755 instead of 0644.

Fix detecting src == dst.

Use a simpler command to copy src -> dst.

Also change echo to printf, get rid of 'echo -n', which is
highly non-portable.


-------- diffstat follows --------
/trunk/scripts/populate.in | 76 43 33 0 +++++++++++++++++++++++++++++-----------------------
1 file changed, 43 insertions(+), 33 deletions(-)
(transplanted from d7ddcb75e0f703e2ba6d17169167356389224870)

 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.