gpgtar: Prefer --set-filename over implicit name
* tools/gpgtar-extract.c: Prefer opt.filename over filename for the directory prefix.
If you would extract from stdin (filename -) and use set-filename
to provide a real filename the "-" would be used for the directory
name. With this change an explicit filename is prefered.
- GnuPG-Bug-Id: T3500
- Signed-off-by: Andre Heinecke <firstname.lastname@example.org>