media: dvb-frontends: drx39xyj: set missing error code

The rc return code was never set in hi_command().

This fixes this smatch warning:

drivers/media/dvb-frontends/drx39xyj/drxj.c:2351 hi_command() warn: missing error code 'rc'

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