PCI/PM: Clear state_saved during suspend

commit 82fee4d67ab86d6fe5eb0f9a9e988ca9d654d765 upstream.

This patch clears pci_dev->state_saved at the beginning of suspending.
PCI config state may be saved long before that.  Some drivers call
pci_save_state() from the ->probe() callback to get snapshot of sane
configuration space to use in the ->slot_reset() callback.

[wangyj: adjust context]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> # add comment
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>