mfd: ti_am335x_tscadc: Fix static checker warning

It is possible that platform_get_resource() might return NULL and
therefore code needs to check for this condition before
de-referencing the pointer.

Therefore move the de-referencing of 'res' pointer after
devm_ioremap_resource() which would have checked the validity of the
pointer.
Reported-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/ti_am335x_tscadc.c

@@ -182,11 +182,11 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 		tscadc->irq = err;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	tscadc->tscadc_phys_base = res->start;
 	tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(tscadc->tscadc_base))
 		return PTR_ERR(tscadc->tscadc_base);
 
+	tscadc->tscadc_phys_base = res->start;
 	tscadc->regmap = devm_regmap_init_mmio(&pdev->dev,
 			tscadc->tscadc_base, &tscadc_regmap_config);
 	if (IS_ERR(tscadc->regmap)) {