staging: lustre: added space before the open parenthesis

added space before the open parenthesis to fix checkpatch error

Signed-off-by: Nandini Hanumanthagowda <nandu.hgowda@gmail.com>
Reviewed-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>