UPSTREAM: Revert "proc: don't allow async path resolution of /proc/thread-self components"

[ Upstream commit 2587890b ]

This reverts commit 0d4370cf.

No longer needed, as the io-wq worker threads have the right identity.

Change-Id: I7a28e02a0a1911555853cf4046e3a09c7e36d4a2
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 87cb08dc)
Bug: 268174392
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>