selftests: drv-net: rss_api: test setting hashing key via Netlink

selftests: drv-net: rss_api: test setting hashing key via Netlink

Test setting hashing key via Netlink.

  # ./tools/testing/selftests/drivers/net/hw/rss_api.py
  TAP version 13
  1..7
  ok 1 rss_api.test_rxfh_nl_set_fail
  ok 2 rss_api.test_rxfh_nl_set_indir
  ok 3 rss_api.test_rxfh_nl_set_indir_ctx
  ok 4 rss_api.test_rxfh_indir_ntf
  ok 5 rss_api.test_rxfh_indir_ctx_ntf
  ok 6 rss_api.test_rxfh_nl_set_key
  ok 7 rss_api.test_rxfh_fields
  # Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0

Link: https://patch.msgid.link/20250716000331.1378807-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>