PCI PM: Read power state from device after trying to change it on resume

pci_restore_standard_config() unconditionally changes current_state
to PCI_D0 after attempting to change the device's power state, but
it should rather read the actual current power state from the
device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>