avfs: use full path of executable

Closes #29418.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
duplicity: use full path of executable

Closes #29420.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
genstats: use full path of executable

Closes #29421.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>