media: staging: cxd2099: Removed useless printing in cxd2099 driver

campoll and read_data are called very often and the printouts are very
annoying and make the driver unusable. They seem to be left over from
developing the buffer mode.

Original code change by Ralph Metzler, modified by Jasmin Jessich to
match current Kernel code.

Signed-off-by: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Jasmin Jessich <jasmin@anw.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>