PCI: Use devm_add_action_or_reset()

devm_add_action_or_reset() is a helper function which internally calls
devm_add_action().  If the devm_add_action() fails, it will execute the
action mentioned and return the error code.

Use devm_add_action_or_reset() to reduce source code size (avoid writing
the action twice) and reduce the likelihood of bugs.

Link: https://lore.kernel.org/r/20190708123354.12127-1-huangfq.daxian@gmail.comSigned-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/controller/pci-host-common.c

@@ -43,9 +43,8 @@ static struct pci_config_window *gen_pci_init(struct device *dev,
 		goto err_out;
 	}
 
-	err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
+	err = devm_add_action_or_reset(dev, gen_pci_unmap_cfg, cfg);
 	if (err) {
-		gen_pci_unmap_cfg(cfg);
 		goto err_out;
 	}
 	return cfg;