`s' cannot be NULL if kmalloc_caches is not NULL.

This conditional would trigger a NULL pointer on `s', anyway, since it is
immediately derefernced if true.
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>