staging: lustre: replaced C99 comment style by C89 style

As per coding style guidelines C89 comment style /*...*/
is preferred over C99 comment style //, hence replaced
C99 comment style by C89 comment style 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>