V4L/DVB: dib7000p: reduce large stack usage

This patch reduces static stack usage of one of the 2 top offenders
as listed by 'make checkstack':

Building with CONFIG_FRAME_WARN=2048 produces:

drivers/media/dvb/frontends/dib7000p.c:1367: warning: the frame size of 2320 bytes is larger than 2048 bytes

and in 'make checkstack', the stack usage goes from:
0x00002409 dib7000p_i2c_enumeration [dib7000p]:		2328
to unlisted with this patch.

Also change one caller of dib7000p_i2c_enumeration() to check its
return value.

I don't have the hardware that is needed to test this patch.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/dvb-usb/cxusb.c b/drivers/media/dvb/dvb-usb/cxusb.c
index 33a83f9..0eb4908 100644
--- a/drivers/media/dvb/dvb-usb/cxusb.c
+++ b/drivers/media/dvb/dvb-usb/cxusb.c
@@ -1025,8 +1025,9 @@
 
 	cxusb_bluebird_gpio_pulse(adap->dev, 0x02, 1);
 
-	dib7000p_i2c_enumeration(&adap->dev->i2c_adap, 1, 18,
-				 &cxusb_dualdig4_rev2_config);
+	if (dib7000p_i2c_enumeration(&adap->dev->i2c_adap, 1, 18,
+				 &cxusb_dualdig4_rev2_config) < 0)
+		return -ENODEV;
 
 	adap->fe = dvb_attach(dib7000p_attach, &adap->dev->i2c_adap, 0x80,
 			      &cxusb_dualdig4_rev2_config);