thermal-core: Fix invalid sensor request not accounted correctly

Add NULL check for sensor name before using it in sensor_get_id and
return NULL explicitly when sensor id is not valid in get_sensor of
thermal core.

Change-Id: I4200a5691183aa2d40ef8ed64554f0beb8ce6d0d
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 739696d..21863e8 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -70,16 +70,19 @@
 
 	list_for_each_entry_safe(pos, var, &sensor_info_list, sensor_list) {
 		if (pos->sensor_id == sensor_id)
-			break;
+			return pos;
 	}
 
-	return pos;
+	return NULL;
 }
 
 int sensor_get_id(char *name)
 {
 	struct sensor_info *pos, *var;
 
+	if (!name)
+		return -ENODEV;
+
 	list_for_each_entry_safe(pos, var, &sensor_info_list, sensor_list) {
 		if (!strcmp(pos->tz->type, name))
 			return pos->sensor_id;