CVE-2025-21879 btrfs: fix use-after-free on inode when scanning root during em shrinking

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free on inode when scanning root during em shrinking At btrfsscanroot we are accessing the inode's root and fsinfo in a call to btrfsfsclosing after we have scheduled the inode for a delayed iput, and that ca...