Linux: fix variable used to test for the iop create API

Linux: fix variable used to test for the iop create API

Use correct variable when testing for the create API to use.

This is just for looks - there is no effect since mkdir and create
were changed in the same kernel release.

Reviewed-on: http://gerrit.openafs.org/7984
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit c633a92a1bc7881f18ee641082ff2efe7da1a8cb)

Change-Id: Ib23fe9a34bc07227614c149b0f16d3b0a067501b
Reviewed-on: http://gerrit.openafs.org/8081
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>