doc: Updated full list of RCU API in whatisRCU.rst

This patch updates the list of RCU API in whatisRCU.rst.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>
Tested-by: Amol Grover <frextrite@gmail.com>
Tested-by: Phong Tran <tranmanphong@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Documentation/RCU/whatisRCU.rst

@@ -884,11 +884,14 @@ in docbook.  Here is the list, by category.
 RCU list traversal::
 
 	list_entry_rcu
+	list_entry_lockless
 	list_first_entry_rcu
 	list_next_rcu
 	list_for_each_entry_rcu
 	list_for_each_entry_continue_rcu
 	list_for_each_entry_from_rcu
+	list_first_or_null_rcu
+	list_next_or_null_rcu
 	hlist_first_rcu
 	hlist_next_rcu
 	hlist_pprev_rcu
@@ -902,7 +905,7 @@ RCU list traversal::
 	hlist_bl_first_rcu
 	hlist_bl_for_each_entry_rcu
 
-RCU pointer/list udate::
+RCU pointer/list update::
 
 	rcu_assign_pointer
 	list_add_rcu
@@ -912,10 +915,12 @@ RCU pointer/list udate::
 	hlist_add_behind_rcu
 	hlist_add_before_rcu
 	hlist_add_head_rcu
+	hlist_add_tail_rcu
 	hlist_del_rcu
 	hlist_del_init_rcu
 	hlist_replace_rcu
-	list_splice_init_rcu()
+	list_splice_init_rcu
+	list_splice_tail_init_rcu
 	hlist_nulls_del_init_rcu
 	hlist_nulls_del_rcu
 	hlist_nulls_add_head_rcu