net: phy: replace mutex_is_locked with lockdep_assert_held in phylib

Switch to lockdep_assert_held(_once), similar to what is being done
in other subsystems. One advantage is that there's zero runtime
overhead if lockdep support isn't enabled.

Signed-off-by: Heiner Kallweit <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/phy/mdio_bus.c

···
 {
 	int retval;
 
-	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+	lockdep_assert_held_once(&bus->mdio_lock);
 
 	retval = bus->read(bus, addr, regnum);
 
···
 {
 	int err;
 
-	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+	lockdep_assert_held_once(&bus->mdio_lock);
 
 	err = bus->write(bus, addr, regnum, val);
 

drivers/net/phy/phy.c

···
 {
 	int err;
 
-	WARN_ON(!mutex_is_locked(&phydev->lock));
+	lockdep_assert_held(&phydev->lock);
 
 	/* Keep previous state if loopback is enabled because some PHYs
 	 * report that Link is Down when loopback is enabled.

drivers/net/phy/phy_device.c

···
 	struct phy_driver *phydrv = phydev->drv;
 	int ret;
 
-	WARN_ON(!mutex_is_locked(&phydev->lock));
+	lockdep_assert_held(&phydev->lock);
 
 	if (!phydrv || !phydrv->resume)
 		return 0;