video: fbdev: mb862xx: mb862xx-i2c: don't print error when adding adapter fails

Don't print error when adding adapter fails. The core will do this for
us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
[tomi.valkeinen@ti.com: fixed the description]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>