net: remove some unless free on failure in alloc_netdev_mqs()

When we jump to free_pcpu on failure in alloc_netdev_mqs()
rx and tx queues are not yet allocated, so no need to free them.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>