scripts+samples: fix listings the samples

Since we use defconfigs to save the samples, listing all the
samples can no longer be done by passing all the sample names
at one to the script; we need to pass them one-by-one after
we expand the sample's defconfig ibnto a complete .config.

Reported-by: Bryan Hundven <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 #!/bin/sh

 set -e

 printf "Running autoconf...\n"

 autoconf -Wall --force

 printf "Done. You may now run:\n    ./configure\n"