media: tc358743: Remove unnecessary self assignment

Clang warns when a variable is assigned to itself.

drivers/media/i2c/tc358743.c:1921:7: warning: explicitly assigning value
of variable of type 'int' to itself [-Wself-assign]
                ret = ret;
                ~~~ ^ ~~~
1 warning generated.

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>