drivers/net/phy/mdio_bus.c: call put_device on device_register() failure

drivers/net/phy/mdio_bus.c: call put_device on device_register() failure

It is required to call put_device() if device_register() fails, so that
we give up the last reference to the device.  Calling put_device allows
for mdiobus_release to be executed, kfreeing the bus.

Signed-off-by: Levente Kurusa <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Grant Likely <[email protected]>
Cc: David Daney <[email protected]>
Cc: David S. Miller <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>