staging: lustre: lnet: use kmalloc/kvmalloc in router_proc

The buffers allocated in router_proc are to temporarily
hold strings created for procfs files.
So they do not need to be zeroed and are safe to use
GFP_KERNEL.
So use kmalloc() directly except in two cases where it
isn't trivial to confirm that the size is always small.
In those cases, use kvmalloc().

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