Extracting symbols v9fs_stat2inode and p9mode2unixmode from fs/9p/vfs_inode.c results in 5x more LoC on 15.[345] codestreams than 15.[26] and upstream kernel

The command below is able to reproduce the issue:

```
klp-build setup --name bsc1226325 --cve 2024-36964 --file-funcs fs/9p/vfs_inode.c v9fs_stat2inode p9mode2unixmode --module 9p --conf CONFIG_9P_FS
```
On upstream, 15.2 and 15.6 codestreams clang-extract generates ~233 LoC, while on 15.3, 15.4 and 15.5 it generates ~1k LoC.