ksmbd: fix same UniqueId for dot and dotdot entries

ksmbd sets the inode number to UniqueId. However, the same UniqueId for
dot and dotdot entry is set to the inode number of the parent inode.
This patch set them using the current inode and parent inode.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>