staging: panel: panel.c: Fixed coding style issues

Fixed warnings reported by checkpatch.pl:
 - Block comments use a trailing */ on a separate line
 - Block comments use * on subsequent lines

Signed-off-by: Nayeemahmed Badebade <itachi.opsrc@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>