mtd/maps/physmap: catch failure to register MTD_PHYSMAP_COMPAT device

If the default Kconfig values are used with MTD_PHYSMAP_COMPAT you end
up with a resource where end < start. This causes __request_resource to
return a conflict which then returns an -EBUSY error code. The current
physmap.c code just assumes that the platfom_device_register will always
succeed.

Catch this failure during the physmap_init and propogate the error.

Signed-off-by: H Hartley Sweeten <[e-mail]>
Reported-by: Randy Dunlap <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

drivers/mtd/maps/physmap.c

···
 
 	err = platform_driver_register(&physmap_flash_driver);
 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
-	if (err == 0)
-		platform_device_register(&physmap_flash);
+	if (err == 0) {
+		err = platform_device_register(&physmap_flash);
+		if (err)
+			platform_driver_unregister(&physmap_flash_driver);
+	}
 #endif
 
 	return err;