libadmin: Fix a lot of dead assignments in vsprocs

Tidy up a lot of places where we initialise a variable, then
immediately assign a proper value to it, or store a return value
that we don't actually care about.

Caught by clang-analyzer

Change-Id: Icf0ec713dac6f2c4f0a60e8ead52a8d3e19381f0
Reviewed-on: http://gerrit.openafs.org/9205
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>