Documentation/cpu-hotplug.txt: fix a typo in example code

As the notifier_block name (i.e.  foobar_cpu_notifer) is different from
the parameter (i.e.foobar_cpu_notifier) of register function, that is
definitely error and it also makes readers confused.

Signed-off-by: Sangjung Woo <[email protected]>
Reviewed-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Documentation/cpu-hotplug.txt

@@ -285,7 +285,7 @@ A: This is what you would need in your kernel code to receive notifications.
 		return NOTIFY_OK;
 	}
 
-	static struct notifier_block foobar_cpu_notifer =
+	static struct notifier_block foobar_cpu_notifier =
 	{
 	   .notifier_call = foobar_cpu_callback,
 	};