simple_file: fix crash if nothing to select
simple_file: fix crash if nothing to select

The simple_dir_filter can come back with no entries, so fix this case

Signed-off-by: James Bottomley <1acebbdca565c7b6b638bdc23b58b5610d1a56b8@Parallels.com>

marineam/efitools,mjg59/efitools,marineam/efitools,marineam/efitools,msekletar/efitools,msekletar/efitools,mjg59/efitools,mjg59/efitools,msekletar/efitools,mjg59/efitools,msekletar/efitools,marineam/efitools