* Fix possible deadlock because of never unlocked mutex during failed unmount.
* Fix segmentation fault after unmounting.
Scenario:
1. Mount path /a
2. Mount path /b
3. Unmount path /b
4. Appempt to read from path /a will throw segmentation fault.
Reason:
The function bindings_alloc correctly allocates memory and sets the index property of the binding. Afterwards the mount function does memset again for the binding and resets the index to zero. Unmounting will now always NULL the binding at position zero. However the actual binding on position zero is still mounted and the next access to it results in segmentation fault.
