cifs: prevent NULL deref in cifscomposemount_options()
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 v5.4.135 by commit f7d1fa65e74263d11f90ddd33b4d4cd905a93759. For more details please see the references link.