net: Remove netif_rx_any_context() and netif_rx_ni().

Remove netif_rx_any_context and netif_rx_ni() because there are no more
users in tree.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>