media: dvb-frontends: drx39xyj: replace return with goto for proper unwind

In three places there was a return instead of a goto to the unwind
code.

This fixes three smatch warnings:

drxj.c:9542 ctrl_get_qam_sig_quality() warn: missing unwind goto?
drxj.c:10919 ctrl_set_standard() warn: missing unwind goto?
drxj.c:11466 drxj_open() warn: missing unwind goto?

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>