percpu: fix percpu accessors to potentially !cpu_possible() cpus: m32r

Impact: CPU iterator bugfixes

Percpu areas are only allocated for possible cpus.  In general, you
shouldn't access random cpu's percpu areas.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NHirokazu Takata <takata@linux-m32r.org>

arch/m32r/kernel/smpboot.c

@@ -592,7 +592,7 @@ int setup_profiling_timer(unsigned int multiplier)
 	 * accounting. At that time they also adjust their APIC timers
 	 * accordingly.
 	 */
-	for (i = 0; i < NR_CPUS; ++i)
+	for_each_possible_cpu(i)
 		per_cpu(prof_multiplier, i) = multiplier;
 
 	return 0;