[media] em28xx-i2c: get rid of the dprintk2 macro

There is only a single place where the dprintk2 macro is used, so get rid of it.

[mchehab@redhat.com: fix checkpathc.pl complain:
 ERROR: space prohibited before that close parenthesis ')']
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>