drivers/base/cpu.c: fix the output from /sys/devices/system/cpu/offline

Without CONFIG_CPUMASK_OFFSTACK, simply inverting cpu_online_mask leads
to CPUs beyond nr_cpu_ids to be displayed twice and CPUs not even
possible to be displayed as offline.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/cpu.c

@@ -186,7 +186,7 @@ static ssize_t print_cpus_offline(struct sysdev_class *class,
 	/* display offline cpus < nr_cpu_ids */
 	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
 		return -ENOMEM;
-	cpumask_complement(offline, cpu_online_mask);
+	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
 	n = cpulist_scnprintf(buf, len, offline);
 	free_cpumask_var(offline);