Skip directories that does NOT have the same magic as /data/app.
This is to avoid scanning incfs and any other stacked filesystems.
While this is way dumber, it's way cheaper.
no kern_path(), no missable path_put(), no ref handling.
This supercedes
`throne_tracker: avoid cross fs access
(https://github.com/tiann/KernelSU/pull/2626)`
- upstream
0b6998b474
Signed-off-by: backslashxx
<118538522+backslashxx@users.noreply.github.com>