ksmbd: add missing calling smb2_set_err_rsp() on error

[ Upstream commit 0e2378ea ]

If some error happen on smb2_sess_setup(), Need to call
smb2_set_err_rsp() to set error response.
This patch add missing calling smb2_set_err_rsp() on error.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>