doc: fix duplicate tag usage in QuickStartUnix

The duplicate LIWQ54 tag appears to break newer versions of fop.  Since it
isn't referenced by anything, just remove in both instances.

Change-Id: Ie996f0110a9114399a1873ebda1eba4c7696f716
Reviewed-on: http://gerrit.openafs.org/11623
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
doc: fix unbalanced <listitem> in AdminGuide/auagd018.xml

This was introduced by c04c57c6c57d2e0b09ba60b68de738b636c9450b

Change-Id: I2dbc558bf97673074c774b457b53b4a4436b43c1
Reviewed-on: http://gerrit.openafs.org/11624
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>