Merge branch 'io_uring-zcrx-fix-selftests-and-add-new-test-for-rss-ctx'

David Wei says:

====================
io_uring/zcrx: fix selftests and add new test for rss ctx

Update io_uring zero copy receive selftest. Patch 1 does a requested
cleanup to use defer() for undoing ethtool actions during the test and
restoring the NIC under test back to its original state.

Patch 2 adds a required call to set hds_thresh to 0. This is needed for
the queue API.

Patch 3 adds a new test case for steering into RSS contexts. A real
application using io_uring zero copy receive relies on this working to
shard work across multiple queues. There seems to be some
differences/bugs with steering into RSS contexts and individual queues.
====================

Link: https://patch.msgid.link/20250425022049.3474590-1-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>