vol: nt_open should not create missing directories

vol: nt_open should not create missing directories

Revert the prior change that added directory creation
to nt_open().  nt_open() should fail and the caller should
create the directories.  Failure to do so results in an
incomplete tree which confuses the salvager.

Reviewed-on: http://gerrit.openafs.org/3709
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 1ad22ed7e14d1ed643add0dbf80c82b96ae69fc8)

Change-Id: I4669ee27bd5c3d9100f3e7fc880d6c32e990493f
Reviewed-on: http://gerrit.openafs.org/3844
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>