Fix for the one-time (dumpfile), or as-required (live system),
gathering of tasks from the kernel pid_hash[] in 2.6.24 and later
kernels.  Without the patch, if an entry in a pid_hash[] chain is
not related to the "init_pid_ns" pid_namespace structure, any
remaining entries in the hlist chain are skipped.
(vvs@parallels.com)