x86: use dev_to_node() to get node for device in dma_alloc_pages()

use dev_to_node() to get node for device in dma_alloc_pages().

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>