extcon: Do not invoke the update() if the status is the same as before

extcon: Do not invoke the update() if the status is the same as before

Do not invoke the update func. if the status is the same as before.
And do not printout error logs for not matched device.
The information of not matched device is already printed out on booting time.
So it's redundant logs.

Change-Id: I8bd2696036bb4633eb05a128d5a9de46dc35fed1
Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>