lwp: Fix possible memory leak from scan-build

lwp: Fix possible memory leak from scan-build

It is possible for LWP_CreateProcess to return early. When it does, it
should free up any memory it allocated before leaving scope.

Reviewed-on: https://gerrit.openafs.org/13080
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 55013a111394052a0253c87a744d03dfabd1be75)

Change-Id: I9112d2039c7c58a707231568e2e84e0340407bac
Reviewed-on: https://gerrit.openafs.org/13122
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: PatRiehecky <jcpunk@gmail.com>
Reviewed-by: Joe Gorse <jhgorse@gmail.com>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>