libdvbv5: move store/retrieve functions upper

We'll need to use those functions earlier.

So, move them to the beginning of the file.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
libdvbv5: better handle ATSC/Annex B

As DVBv3 is confusing with regards to ATSC and ClearQAM (DVB-C
annex B), userpace apps also only differenciate between ATSC and
ClearQAM via modulation.

However, when using DVBv5, may be using the delivery system
in order to enforce one or the other.

In any case, the DVB API should clearly identify between ATSC
and ClearQAM.

So, make the API to better handle it, fixing the delivery
system if needed, when reading or write a file.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
v4l2-ctl: errors during streaming setup were ignored

If an ioctl like VIDIOC_QBUF returned an error during the
setup of the streaming, then that was ignored which caused
the streaming loop to just wait for a buffer to arrive.

Report the error correctly and bail out if an error occurs.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>