V4L/DVB (8837): dvb: fix I2C adapters name size

Some DVB drivers are incorrectly assuming that the size of
i2c_adapter.name is I2C_NAME_SIZE.  Here's a fix.

Also change strncpy to strlcpy, as the former is error-prone (and was
indeed incorrectly used.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Uwe Bugla <uwe.bugla@gmx.de>
Reviewed-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>