rcutorture: Fix expected forward progress duration in OOM notifier

The rcutorture_oom_notify() function has a misplaced close parenthesis
that results in increasingly long delays in rcu_fwd_progress_check()'s
checking for various RCU forward-progress problems.  This commit therefore
puts the parenthesis in the right place.
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

kernel/rcu/rcutorture.c

@@ -1843,7 +1843,7 @@ static int rcutorture_oom_notify(struct notifier_block *self,
 	WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
 	     __func__);
 	rcu_torture_fwd_cb_hist();
-	rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat) / 2));
+	rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat)) / 2);
 	WRITE_ONCE(rcu_fwd_emergency_stop, true);
 	smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
 	pr_info("%s: Freed %lu RCU callbacks.\n",