[BUG]: file related dev field extraction is dependent on the Filesystem type

[FedeDP]

During the development of ppc64 me and @Andreagit97 noticed that some open related tests were failing to assert the dev field:

Expected equality of these values:
 *(T*)(m_event_params[m_current_param].valptr)
   Which is: 29
 param
   Which is: 37

Digging into it, we noticed that vfs_getattr_nosec calls a filesystem dependent getattr callback (https://elixir.bootlin.com/linux/v6.7.7/source/fs/stat.c#L135), that, for btrfs (the filesystem being used by our ppc64 test node), sets dev field differently: https://elixir.bootlin.com/linux/v6.7.7/source/fs/btrfs/inode.c#L8692.

See the call trace:

@[
    generic_fillattr+12
    btrfs_getattr+228
    vfs_getattr_nosec+244
    vfs_fstat+128
    __do_sys_newfstat+80
    system_call_exception+372
    system_call_vectored_common+348
]: 2

This means that our dev field is FS dependent and thus it cannot be relied upon.
There is no way to fix this (at least on eBPF probes), since we miss the needed helpers.

[FedeDP]

/milestone TBD