pwm: omap-dmtimer: Potential NULL dereference on error

"omap" is NULL so we can't dereference it.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-omap-dmtimer.c

@@ -243,7 +243,7 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
 
 	omap = devm_kzalloc(&pdev->dev, sizeof(*omap), GFP_KERNEL);
 	if (!omap) {
-		omap->pdata->free(dm_timer);
+		pdata->free(dm_timer);
 		return -ENOMEM;
 	}