Reapply "io_uring: drop any code related to SCM_RIGHTS"

This reverts commit 81cc178d which was a
revert of commit a3812a47 which is
commit 6e5e6d27 upstream.

It brings it back in an abi-safe way.

Bug: 338889538
Change-Id: I5e2fd45fb4d972056728fb9963a9ef9f86e9a6ca
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>