src/vfs/undelfs/undelfs.c: fix memory leaks.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
(sftpfs_open_file): fix memory leak.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
(panel_get_field_by_title): fix memory leak.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>