This patch fixes up two places whre dma64_addr_t is used incorrectly.
Note that pci_dev->dma_mask and the second argument to
blk_queue_bounce_limit() are both u64, so the old types clearly are
wrong (besides, dma64_addr_t is supposed to be used only with the
pci_dac_*() routines, as per DaveM's earlier mail).

	--david