Increasing WARNS seems to have broken compilation of this utility.
Instead of lowering WARNS, just fix to code to compile properly.
Submitted by: <bf2006a yahoo com>
Tested by: bms
execvp() in the child branch of a vfork(). Changed to use fork()
instead.
Some of these (mv, find, apply, xargs) might benefit greatly from
being rewritten to use vfork() properly.
PR: Loosely related to bin/8252
Approved by: jkh and bde