PCI: Fix device class print out

Found debug print of class is shifted.

| pci 0000:f8:15.2: [8086:2b56] type 0 class 0x000600

Code is trying to print class with 6 digits, but use shifted class with
4 digits valid value as variable.

Change to original dev->class directly.

Also remove not needed calculating of local variable class, because it
will be updated after pci_fixup_device(pci_fixup_early...)

Also unify type print out when class and header is not matched.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>