thermal: exynos: Correct sanity check at exynos_report_trigger() function

Up till now, by mistake, wrong variable was tested against being NULL.
Since exynos_report_trigger() is always called with valid p pointer,
it is only necessary to check if a valid thermal zone device is passed.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/samsung/exynos_tmu.c

@@ -172,8 +172,8 @@ static void exynos_report_trigger(struct exynos_tmu_data *p)
 	unsigned long temp;
 	unsigned int i;
 
-	if (!p) {
-		pr_err("Wrong temperature configuration data\n");
+	if (!tz) {
+		pr_err("No thermal zone device defined\n");
 		return;
 	}