[media] gspca - zc3xx: Fix bad sensor values when changing autogain

The setexposure added in commit 590f21680616 works only for the sensor hv7131r,
but it is called for all sensors when changing the autogain.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/zc3xx.c

@@ -5884,6 +5884,8 @@ static void getexposure(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 
+	if (sd->sensor != SENSOR_HV7131R)
+		return;
 	sd->ctrls[EXPOSURE].val = (i2c_read(gspca_dev, 0x25) << 9)
 		| (i2c_read(gspca_dev, 0x26) << 1)
 		| (i2c_read(gspca_dev, 0x27) >> 7);
@@ -5894,6 +5896,8 @@ static void setexposure(struct gspca_dev *gspca_dev)
 	struct sd *sd = (struct sd *) gspca_dev;
 	int val;
 
+	if (sd->sensor != SENSOR_HV7131R)
+		return;
 	val = sd->ctrls[EXPOSURE].val;
 	i2c_write(gspca_dev, 0x25, val >> 9, 0x00);
 	i2c_write(gspca_dev, 0x26, val >> 1, 0x00);