media: i2c: adv748x: Fix cleanup jump on chip identification

The error handling for the adv748x_identify_chip() call erroneously
jumps to the err_cleanup_clients label before the clients have been
established.

Correct this by jumping to the next (and correct) label in the cleanup
code: err_cleanup_dt.

Fixes: 3e89586a ("media: i2c: adv748x: add adv748x driver")

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>