PCI / PCIe portdrv: Fix pcie_portdrv_slot_reset()

After commit c82f63e4


(PCI: check saved state before restore) pcie_portdrv_slot_reset()
may not work correctly if dev->error_state is equal to
pci_channel_io_frozen, because dev->state_saved need not be set at
that time.  Fix this issue by setting dev->state_saved before
pci_restore_state() is called in pcie_portdrv_slot_reset().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>