Properly renew expired credentials
When a caller imports expired credentials, we aim to actually renew them
if we can. However due to incorrect checks and not clearing of the
ret_maj variable after checks we end up returning an error instead.
Also fix mechglue to also save and properly report the first call errors
when both remote and local fail.
Resolves: #170
Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Robbie Harwood <rharwood@redhat.com>