srcu: Release early_srcu resources when no longer in use

Kernels built with the CONFIG_TREE_SRCU Kconfig option set and then
booted with rcupdate.rcu_self_test=1 and srcutree.convert_to_big=1 will
test Tree SRCU during early boot.  The early_srcu structure's srcu_node
array will be allocated when init_srcu_struct_fields() is invoked,
but after the test completes this early_srcu structure will not be used.

This commit therefore invokes cleanup_srcu_struct() to free that srcu_node
structure.
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

kernel/rcu/update.c

@@ -586,6 +586,7 @@ static int rcu_verify_early_boot_tests(void)
 		early_boot_test_counter++;
 		srcu_barrier(&early_srcu);
 		WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie));
+		cleanup_srcu_struct(&early_srcu);
 	}
 	if (rcu_self_test_counter != early_boot_test_counter) {
 		WARN_ON(1);