Merge branch 'bpf: devmap: provide rxq after redirect'

Florian Kauer says:

====================
rxq contains a pointer to the device from where
the redirect happened. Currently, the BPF program
that was executed after a redirect via BPF_MAP_TYPE_DEVMAP*
does not have it set.

Add bugfix and related selftest.

---
Changes in v4:
- return -> goto out_close, thanks Toke
- Link to v3: https://lore.kernel.org/r/20240909-devel-koalo-fix-ingress-ifindex-v3-0-66218191ecca@linutronix.de

Changes in v3:
- initialize skel to NULL, thanks Stanislav
- Link to v2: https://lore.kernel.org/r/20240906-devel-koalo-fix-ingress-ifindex-v2-0-4caa12c644b4@linutronix.de

Changes in v2:
- changed fixes tag
- added selftest
- Link to v1: https://lore.kernel.org/r/20240905-devel-koalo-fix-ingress-ifindex-v1-1-d12a0d74c29c@linutronix.de
====================

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>