Treat stale manifests as such, not as 'failed to parse'

There is currently dead code in mft_parse() that handles stale
manifests by setting the stale flag and removing all files they
reference.  This code was made unreachable in a refactor that
fixed a logic error that made mft_parse() succeed despite its
error handling.  check_validity() returns three possible values.
Report failures and stale mfts back immediately via rc.  Success
needs to reset rc to -1, so subsequent errors are reported as
such.

This is mostly cosmetic and only changes the rpki-client output
in that the comment at the top of the config now actually shows
stale manifests. This makes regress pass again.

ok claudio job

0 files changed, 0 insertions, 0 deletions