util: remove dup include

Change-Id: I415dbcae5ae549b6347286ecdee5717fb66cc012
Reviewed-on: http://gerrit.openafs.org/10319
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Christof Hanke <christof.hanke@rzg.mpg.de>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>