ia64/topology: Remove cpus_allowed manipulation

The CPU hotplug callback fiddles with the cpus_allowed pointer to pin the
calling thread on the plugged CPU. That's already guaranteed by the hotplug
core code.

Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/20170412201042.174518069@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/ia64/kernel/topology.c

@@ -355,18 +355,12 @@ static int cache_add_dev(unsigned int cpu)
 	unsigned long i, j;
 	struct cache_info *this_object;
 	int retval = 0;
-	cpumask_t oldmask;
 
 	if (all_cpu_cache_info[cpu].kobj.parent)
 		return 0;
 
-	oldmask = current->cpus_allowed;
-	retval = set_cpus_allowed_ptr(current, cpumask_of(cpu));
-	if (unlikely(retval))
-		return retval;
 
 	retval = cpu_cache_sysfs_init(cpu);
-	set_cpus_allowed_ptr(current, &oldmask);
 	if (unlikely(retval < 0))
 		return retval;