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.

Change-Id: I9e43cc80d3817ee8a6c339c4ae98a1a2ab0851a1
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>