stop_machine.h: "disables preeempt" -> "disables preemption"

Use the noun instead of a misspelled verb.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

include/linux/stop_machine.h

@@ -94,7 +94,7 @@ static inline int try_stop_cpus(const struct cpumask *cpumask,
  * stop_machine "Bogolock": stop the entire machine, disable
  * interrupts.  This is a very heavy lock, which is equivalent to
  * grabbing every spinlock (and more).  So the "read" side to such a
- * lock is anything which disables preeempt.
+ * lock is anything which disables preemption.
  */
 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)