staging: lustre: lnet-route: use kmalloc for small allocation

This allocation is reasonably small.
As the function is called "*_locked", it might not be safe
to perform a GFP_KERNEL allocation, so be safe and
use GFP_NOFS.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>