i2c: rely on driver core when sanitizing devices

Commit 0998d063 (device-core: Ensure drvdata = NULL when no driver
is bound) modified the driver core to always clear .driver and .drvdata
on remove or probe error. No need for the I2C core to do it.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>