decode_bar() and pci_calc_resource_flags() both looked at the PCI BAR
type information, and it's simpler to just do it all in one place.

decode_bar() sets IORESOURCE_IO, IORESOURCE_MEM, and IORESOURCE_MEM_64
as appropriate, so res->flags contains all the information pci_bar_type
does, so we don't need to test the pci_bar_type return value.

decode_bar() used to return pci_bar_type, which we no longer need.  We
can simplify it a bit by returning the struct resource flags rather than
updating them internally.

In pci_update_resource(), there's no need to decode the BAR type bits
again; we can just test for IORESOURCE_MEM_64 directly.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>