V4L/DVB (4525): Drivers/media/dvb/dvb-usb/dibusb-mb.c: NULL dereference

V4L/DVB (4525): Drivers/media/dvb/dvb-usb/dibusb-mb.c: NULL dereference

The Coverity checker spotted the following "we dereference d->fe only
when we know it's NULL" bug:
<--  snip  -->
...
static int dibusb_dib3000mb_frontend_attach(struct dvb_usb_device *d)
{
...
if ((d->fe = dib3000mb_attach(&demod_cfg,&d->i2c_adap,&st->ops)) == NULL) {
d->fe->ops.tuner_ops.init = dvb_usb_tuner_init_i2c;
d->fe->ops.tuner_ops.set_params = dvb_usb_tuner_set_params_i2c;
return -ENODEV;
}
...
<--  snip  -->

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>