Prevent infinite loop (with logging) in child process reaping.

Prevent infinite loop (with logging) in child process reaping.

From the perl docs on waitpid:

Note that on some systems, a return value of "-1" could mean that child processes are being automatically reaped.  See perlipc for details, and for other examples.

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1865 9efc2488-bf62-4759-914b-345cdb29e865