thermal: exynos: fix error return code

Set the return variable to an error code as done elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/samsung/exynos_tmu.c

@@ -205,6 +205,7 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
 skip_calib_data:
 	if (pdata->max_trigger_level > MAX_THRESHOLD_LEVS) {
 		dev_err(&pdev->dev, "Invalid max trigger level\n");
+		ret = -EINVAL;
 		goto out;
 	}