cleanup potpourri.h references

Clean up references to a header file which was removed some time ago.

Reviewed-on: http://gerrit.openafs.org/10318
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit 38fc16ddbf1e5477050db21c94d55f75bdadf80b)

Change-Id: Ibb62c0f74b1ea0906d4379c37d2cf8b977d14e16
Reviewed-on: http://gerrit.openafs.org/10473
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>