smb: client: add ParentLeaseKey support

According to MS-SMB2 3.2.4.3.8, when opening a file the client must
lookup its parent directory, copy that entry’s LeaseKey into
ParentLeaseKey, and set SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET.

Extend lease context functions to carry a parent_lease_key and
lease_flags and to add them to the lease context buffer accordingly in
smb3_create_lease_buf. Also add a parent_lease_key field to struct
cifs_fid and lease_flags to cifs_open_parms.

Only applies to the SMB 3.x dialect family.

Fixes: f047390a ("CIFS: Add create lease v2 context for SMB3")
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>