shinpei0208/gdev — pull request #3 by kris7topher (2012-07-08 15:56:04+00:00)
Title: gdev: graceful exit even after failed init

Repeated calls to gdev_major_exit will not cause a kernel panic.

If gdev_major_init fails, it will call gdev_major_exit. At module unload, gdev_major_exit is called again.
This might result in a kernel panic, which makes writing and testing gdev code extremely time-consuming.

In this patch, this issue is fixed by introducing some null checks into gdev_major_exit and related code.
Thus it is safe the call gdev_major_exit several times in a row, effectively making the second and later calls
a no-op.