staging: omap-thermal: fix error check in omap_thermal_expose_sensor() and in omap_thermal_register_cpu_cooling().

The omap_bandgap_get_sensor_data() function returns ERR_PTR(), so we need to use
IS_ERR() rather than a NULL check.

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/omap-thermal/omap-thermal-common.c

@@ -260,7 +260,7 @@ int omap_thermal_expose_sensor(struct omap_bandgap *bg_ptr, int id,
 
 	data = omap_bandgap_get_sensor_data(bg_ptr, id);
 
-	if (!data)
+	if (IS_ERR(data))
 		data = omap_thermal_build_data(bg_ptr, id);
 
 	if (!data)
@@ -309,7 +309,7 @@ int omap_thermal_register_cpu_cooling(struct omap_bandgap *bg_ptr, int id)
 	struct omap_thermal_data *data;
 
 	data = omap_bandgap_get_sensor_data(bg_ptr, id);
-	if (!data)
+	if (IS_ERR(data))
 		data = omap_thermal_build_data(bg_ptr, id);
 
 	if (!data)