drm/gma500/oaktrail_lvds: fix hang on init failure

In the Linux kernel, the following vulnerability has been resolved:

drm/gma500/oaktrail_lvds: fix hang on init failure

The LVDS init code looks up an I2C adapter using i2c_get_adapter() and

tries to read the EDID before falling back to allocating and registering

its own adapter.

The error handling does not separate these cases so on a late init

failure it will try to deregister and free also an adapter that had

previously been registered. Since i2c_get_adapter() takes another

reference to the adapter, deregistration hangs indefinitely while

waiting for the reference to be released.

Fix this by only destroying adapters allocated during LVDS init on

errors.