net/macb: remove useless calls of devm_free_irq()

Inside macb_probe(), when devm_request_irq() fails on queue q, there is no need
to call devm_free_irq() on queues 0..q-1 because the managed device resources
are released later when calling free_netdev().

Also removing devm_free_irq() call from macb_remove() for the same reason.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>