media: ts2020: Variable "utmp" in function ts2020_set_tuner_rf() could be uninitialized

In function ts2020_set_tuner_rf(), local variable "utmp" could
be uninitialized if function regmap_read() returns -EINVAL.
However, this value is used in if statement and written to
the register, which is potentially unsafe.
Signed-off-by: Yizhuo <yzhai003@ucr.edu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/dvb-frontends/ts2020.c

@@ -180,6 +180,9 @@ static int ts2020_set_tuner_rf(struct dvb_frontend *fe)
 	unsigned int utmp;
 
 	ret = regmap_read(dev->regmap, 0x3d, &utmp);
+	if (ret)
+		return ret;
+
 	utmp &= 0x7f;
 	if (utmp < 0x16)
 		utmp = 0xa1;