pwm: Use kcalloc() instead of kzalloc()

kcalloc() should be preferred for allocations of arrays over kzalloc()
with multiplication.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index bc0c20ac..2a1a2d5 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -255,7 +255,7 @@
 	if (ret < 0)
 		goto out;
 
-	chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
+	chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
 	if (!chip->pwms) {
 		ret = -ENOMEM;
 		goto out;