erofs/zmap.c: Fix incorrect offset calculation
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 v6.1.10 by commit 9f31d8c889d9a4e47bfcc6c4537d0c9f89fe582c. For more details please see the references link.