CVE-2025-40205 btrfs: avoid potential out-of-bounds in btrfs_encode_fh()

In the Linux kernel, the following vulnerability has been resolved: btrfs: avoid potential out-of-bounds in btrfsencodefh The function btrfsencodefh does not properly account for the three cases it handles. Before writing to the file handle fh, the function only returns to the user...