percpu: clean up percpu variable definitions

Percpu variable definition is about to be updated such that all percpu
symbols including the static ones must be unique.  Update percpu
variable definitions accordingly.

* as,cfq: rename ioc_count uniquely

* cpufreq: rename cpu_dbs_info uniquely

* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it

* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and
  rename it

* ipv4,6: rename cookie_scratch uniquely

* x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to
  pmc_irq_entry and nmi_entry to pmc_nmi_entry

* perf_counter: rename disable_count to perf_disable_count

* ftrace: rename test_event_disable to ftrace_test_event_disable

* kmemleak: rename test_pointer to kmemleak_test_pointer

* mce: rename next_interval to mce_next_interval

[ Impact: percpu usage cleanups, no duplicate static percpu var names ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index aa08be6..54b1de5 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1318,7 +1318,7 @@
 
 #ifdef CONFIG_FUNCTION_TRACER
 
-static DEFINE_PER_CPU(atomic_t, test_event_disable);
+static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
 
 static void
 function_test_events_call(unsigned long ip, unsigned long parent_ip)
@@ -1334,7 +1334,7 @@
 	pc = preempt_count();
 	resched = ftrace_preempt_disable();
 	cpu = raw_smp_processor_id();
-	disabled = atomic_inc_return(&per_cpu(test_event_disable, cpu));
+	disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
 
 	if (disabled != 1)
 		goto out;
@@ -1352,7 +1352,7 @@
 	trace_nowake_buffer_unlock_commit(event, flags, pc);
 
  out:
-	atomic_dec(&per_cpu(test_event_disable, cpu));
+	atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
 	ftrace_preempt_enable(resched);
 }