nvme-pci: DMA unmap the correct regions in nvme_free_sgls

nvme-pci: DMA unmap the correct regions in nvme_free_sgls

The call to nvme_free_sgls() in nvme_unmap_data() has the sg_list and sge
parameters swapped.  This wasn't noticed by the compiler because both share
the same type.  On a Xen PV hardware domain, and possibly any other
architectures that takes that path, this leads to corruption of the NVMe
contents.

Fixes: f0887e2a52d4 ("nvme-pci: create common sgl unmapping helper")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>