libata: fix native mode disabled port handling

Disabled port handling in ata_pci_init_native_mode() is slightly
broken in that it may end up using the wrong port_info.  This patch
updates it such that disables ports are made dummy as done in the
legacy and other cases.

While at it, fix indentation in ata_resources_present().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>