Revert "exec: don't WARN for racy path_noexec check"

Revert "exec: don't WARN for racy path_noexec check"

This reverts commit d62ba2a5536df83473a2ac15ab302258e3845251 which is
commit 0d196e7589cefe207d5d41f37a0a28a1fdeeb7c6 upstream.

A later commit needs to be reverted so revert this one as well to allow
that to happen properly.

Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>