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 v5.4.200 by commit d0c3730f2763770842e7ffe55ddb251b0132c91d, it was introduced in version v5.4.159 by commit 199acd8c110e3ae62833c24f632b0bb1c9f012a9. For more details please see the references link.