staging: lustre: use BIT macro

This commit changes changes left shift operator to use BIT macro

Signed-off-by: Keerthi Reddy <keerthigd4990@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>