docs: networking: Use netif_rx().

Since commit
   baebdf48 ("net: dev: Makes sure netif_rx() can be invoked in any context.")

the function netif_rx() can be used in preemptible/thread context as
well as in interrupt context.

Use netif_rx().

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/timestamping.rst

@@ -668,7 +668,7 @@ timestamping:
   (through another RX timestamping FIFO). Deferral on RX is typically
   necessary when retrieving the timestamp needs a sleepable context. In
   that case, it is the responsibility of the DSA driver to call
-  ``netif_rx_ni()`` on the freshly timestamped skb.
+  ``netif_rx()`` on the freshly timestamped skb.
 
 3.2.2 Ethernet PHYs
 ^^^^^^^^^^^^^^^^^^^