ksmbd: add missing calling smb2_set_err_rsp() on error

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>

fs/smb/server/smb2pdu.c

@@ -1904,6 +1904,7 @@ int smb2_sess_setup(struct ksmbd_work *work)
 				ksmbd_conn_set_need_negotiate(conn);
 			}
 		}
+		smb2_set_err_rsp(work);
 	} else {
 		unsigned int iov_len;