comedi: vmk80xx: fix expression for tx buffer size
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 v4.14.285 by commit 822e23038ee0a81590f0a6b0ee4a70c67951c496, it was introduced in version v4.14.255 by commit 40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7. For more details please see the references link.