[PA-RISC] Fix must_check warnings in drivers.c

Panic if we can't register the parisc bus or the root parisc device.
There's no way we can boot without them, so let the user know ASAP.

If we can't register a parisc device, handle the failure gracefully.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>

arch/parisc/kernel/drivers.c

@@ -424,7 +424,10 @@ struct parisc_device * create_tree_node(char id, struct device *parent)
 	/* make the generic dma mask a pointer to the parisc one */
 	dev->dev.dma_mask = &dev->dma_mask;
 	dev->dev.coherent_dma_mask = dev->dma_mask;
-	device_register(&dev->dev);
+	if (!device_register(&dev->dev)) {
+		kfree(dev);
+		return NULL;
+	}
 
 	return dev;
 }
@@ -850,8 +853,10 @@ static void print_parisc_device(struct parisc_device *dev)
  */
 void init_parisc_bus(void)
 {
-	bus_register(&parisc_bus_type);
-	device_register(&root);
+	if (!bus_register(&parisc_bus_type))
+		panic("Could not register PA-RISC bus type\n");
+	if (!device_register(&root))
+		panic("Could not register PA-RISC root device\n");
 	get_device(&root);
 }