Documentation: Rename rcu_node_context_switch() to rcu_note_context_switch()

While Paul was explaining some RCU magic I noticed a typo in
rcu_note_context_switch().  As a result, this commit replaces
rcu_node_context_switch() with rcu_note_context_switch().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst

@@ -423,7 +423,7 @@ wait on.
 +-----------------------------------------------------------------------+
 
 If the CPU does a context switch, a quiescent state will be noted by
-``rcu_node_context_switch()`` on the left. On the other hand, if the CPU
+``rcu_note_context_switch()`` on the left. On the other hand, if the CPU
 takes a scheduler-clock interrupt while executing in usermode, a
 quiescent state will be noted by ``rcu_sched_clock_irq()`` on the right.
 Either way, the passage through a quiescent state will be noted in a

Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg

@@ -3880,7 +3880,7 @@
          font-style="normal"
          y="-4418.6582"
          x="3745.7725"
-         xml:space="preserve">rcu_node_context_switch()</text>
+         xml:space="preserve">rcu_note_context_switch()</text>
     </g>
     <g
        transform="translate(1881.1886,54048.57)"

Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg

@@ -753,7 +753,7 @@
          font-style="normal"
          y="-4418.6582"
          x="3745.7725"
-         xml:space="preserve">rcu_node_context_switch()</text>
+         xml:space="preserve">rcu_note_context_switch()</text>
     </g>
     <g
        transform="translate(3131.2648,-585.6713)"