PCI: Protect restore with device lock to be consistent

Commit b014e96d1abb ("PCI: Protect pci_error_handlers->reset_notify() usage
with device_lock()") added protection around pci_dev_restore() function so
a device-specific remove callback does not cause a race condition with
hotplug.

pci_dev_lock() usage has been forgotten in two places.  Add locks for
pci_slot_restore() and moving pci_dev_restore() inside the locks for
pci_try_reset_function().

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

drivers/pci/pci.c

@@ -4517,9 +4517,9 @@ int pci_try_reset_function(struct pci_dev *dev)
 
 	pci_dev_save_and_disable(dev);
 	rc = __pci_reset_function_locked(dev);
+	pci_dev_restore(dev);
 	pci_dev_unlock(dev);
 
-	pci_dev_restore(dev);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(pci_try_reset_function);
@@ -4727,7 +4727,9 @@ static void pci_slot_restore(struct pci_slot *slot)
 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
 		if (!dev->slot || dev->slot != slot)
 			continue;
+		pci_dev_lock(dev);
 		pci_dev_restore(dev);
+		pci_dev_unlock(dev);
 		if (dev->subordinate)
 			pci_bus_restore(dev->subordinate);
 	}