s3:smbd: allow reset_share_mode_entry() to handle more than one durable handle

s3:smbd: allow reset_share_mode_entry() to handle more than one durable handle

This means that multiple durable handles with RH leases can
co-exist now... Before only the last remaining durable handle
was able to pass the SMB_VFS_DURABLE_DISCONNECT() step.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15649
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15651

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>