mcb: fix error handling in mcb_alloc_bus()

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

mcb: fix error handling in mcb_alloc_bus()

There are two bugs:

1) If ida_simple_get() fails then this code calls put_device(carrier)

but we haven't yet called get_device(carrier) and probably that

leads to a use after free.

2) After device_initialize() then we need to use put_device() to

release the bus. This will free the internal resources tied to the

device and call mcb_free_bus() which will free the rest.