device.h: move kobj_to_dev() to use container_of_const()

Instead of rolling our own const-checking logic, use the newly
introduced container_of_const() to handle it all for us automatically.

Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221205121206.166576-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: gregkh

include/linux/device.h

@@ -680,26 +680,7 @@ struct device_link {
 	bool supplier_preactivated; /* Owned by consumer probe. */
 };
 
-static inline struct device *__kobj_to_dev(struct kobject *kobj)
-{
-	return container_of(kobj, struct device, kobj);
-}
-
-static inline const struct device *__kobj_to_dev_const(const struct kobject *kobj)
-{
-	return container_of(kobj, const struct device, kobj);
-}
-
-/*
- * container_of() will happily take a const * and spit back a non-const * as it
- * is just doing pointer math.  But we want to be a bit more careful in the
- * driver code, so manually force any const * of a kobject to also be a const *
- * to a device.
- */
-#define kobj_to_dev(kobj)					\
-	_Generic((kobj),					\
-		 const struct kobject *: __kobj_to_dev_const,	\
-		 struct kobject *: __kobj_to_dev)(kobj)
+#define kobj_to_dev(__kobj)	container_of_const(__kobj, struct device, kobj)
 
 /**
  * device_iommu_mapped - Returns true when the device DMA is translated