This patches fixes the probe error path by cleaning up probed ports, to
avoid leaving registered net devices when the driver failed to probe.

Fixes: 3f518509 ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>