libadmin: Don't pass garbage to pts_UserCreate

libadmin: Don't pass garbage to pts_UserCreate

The libadmin pts_UserCreate function uses the value passed to
it in newUserId to control whether the user is being created
with a user supplied ID or not.

Initialise this value in the caller, so we don't end up creating
users with corrupt ids.

Caught by clang (#985979)

Reviewed-on: http://gerrit.openafs.org/9401
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 5cf4415c8ad400a92fc9c7f436ae52256db2ef09)

Change-Id: I0e91352a98f63b386185abf9860dc056cb775821
Reviewed-on: http://gerrit.openafs.org/11050
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>