tracing: Prefer kcalloc over kzalloc with multiply

Use kcalloc for allocating an array instead of kzalloc with multiply,
as that is what kcalloc is used for.
Found with checkpatch.

Link: http://lkml.kernel.org/r/1433835155-6894-2-git-send-email-gilf@ezchip.com

Signed-off-by: Gil Fruchter <gilf@ezchip.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -3035,7 +3035,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (!iter)
 		return ERR_PTR(-ENOMEM);
 
-	iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
+	iter->buffer_iter = kcalloc(num_possible_cpus(), sizeof(*iter->buffer_iter),
 				    GFP_KERNEL);
 	if (!iter->buffer_iter)
 		goto release;