have_range: open the subid db if needed

have_range: open the subid db if needed

When we run for instance

  check_subid_range ubuntu u 100000 65536

when ubuntu user is defined and has that range, it returns no entries
because the subid db is not opened.  Open it in have_range if needed.

I haven't figured out why this ever worked.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
Cherry-picked-from: 75ea679799a9 ("have_range: open the subid db if needed")
Signed-off-by: Alejandro Colomar <alx@kernel.org>