mcb: fix error handling in mcballocbus()
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 v5.14.9 by commit 9fc198f415dee070a1de957bb5bf5921d8df3499, it was introduced in version v4.7 by commit 5d9e2ab9fea4cdf0a2522f5cbed2e7fbb220d757. For more details please see the references link.