Make it clear that a failure in dib0700_i2c_enumeration is a fatal condition
and we cannot continue.  If the failure occurs, do not attempt to attach to
the tuner.

Problem Noticed the issue when debugging an i2c issue a YUAN High-Tech
STK7700PH for user Roshan Karki <roshan@olenepal.org>.
Signed-off-by: Devin Heitmueller <dheitmueller@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>