lockstat: repair erronous contention statistics

Fix bad contention counting in /proc/lock_stat.

/proc/lockstat tries to gather per-ip contention
statistics per-lock.  This was failing due to
a garbage per-ip index selector being used.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/lockdep.c

@@ -3029,7 +3029,7 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
 
 	stats = get_lock_stats(hlock_class(hlock));
 	if (point < ARRAY_SIZE(stats->contention_point))
-		stats->contention_point[i]++;
+		stats->contention_point[point]++;
 	if (lock->cpu != smp_processor_id())
 		stats->bounces[bounce_contended + !!hlock->read]++;
 	put_lock_stats(stats);