media: dvb_frontend: cleanup some coding style errors

This is a core media file... it shoudn't have so many coding
style issues! The last patch ended by being submitted with
an error like that, very likely due to some cut and paste
issue.

Maybe it is time to clean it up. Do it with the auto
fix logic:

 ./scripts/checkpatch.pl -f drivers/media/dvb-core/dvb_frontend.c --strict --fix-inplace

Then manually fix the errors introduced by it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>