redhat: avoid picking up stray editor backups when processing configs

Emacs and vim both use a trailing '' to designate a backup file. This can cause puzzling behavior in the config generation logic because the build_configs.sh script will pick up both CONFIG_FOO and CONFIG_FOO, which presumably have different values. Just avoid this by filtering out files with ~ extension when picking up CONFIGS from a directory.

Signed-off-by: Clark Williams williams@redhat.com