Fail gracefully if "cd subdir" fails during a make... without this

it would go into an infinite make loop and consume all
processes/resources.

Reviewed by:	Jim Jagielski, Ken Coar


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79659 13f79535-47bb-0310-9956-ffa450edef68