Staging: lustre: fix some coding style

This patch remove unnecessary bracket.

Signed-off-by: Gauthier Voron <gauthier.voron@lip6.fr>
Signed-off-by: Hakan Metin <hakan.metin@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>