nbd: fix race between nbdallocconfig() and module removal
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.4.198 by commit 8a7da4ced236ce6637fe70f14ca18e718d4bf9e9. For more details please see the references link.