pwm: sti: Use devm_kcalloc() instead of calculating the size for devm_kzalloc()

Using a multiplication to calculate the size of an allocation isn't
recommended in case the mulitplication overflows. While the chance this
happens is low, preventing such an error is easy enough; so do that.

Link: https://lore.kernel.org/r/17062aef42e6677629a056e25c6916d8b6eaedeb.1710068192.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-sti.c

@@ -613,7 +613,8 @@ static int sti_pwm_probe(struct platform_device *pdev)
 			return dev_err_probe(dev, PTR_ERR(pc->cpt_clk),
 					     "failed to get PWM capture clock\n");
 
-		pc->ddata = devm_kzalloc(dev, pc->cpt_num_devs * sizeof(*pc->ddata), GFP_KERNEL);
+		pc->ddata = devm_kcalloc(dev, pc->cpt_num_devs,
+					 sizeof(*pc->ddata), GFP_KERNEL);
 		if (!pc->ddata)
 			return -ENOMEM;
 	}