[LTP] wait4 pid_max fix

[Jeff B. <jb...@ra...>]

More from the hppa camp... =)

This is the same fix as an earlier patch, but applied to wait402.c. 
pid_max is available under /proc and should be retrieved from there
rather than from a constant which is no longer exported to userspace.

Tks,
Jeff Bailey

-- 
I do not agree with a word you say, but I will defend to the death your
right to say it. 
 - Voltaire