ksmbd: use goto instead of duplicating the resoure cleanup in ksmbd_open_fd

Use goto instead of duplicating the resoure cleanup in ksmbd_open_fd.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>