Merge r613260 from trunk:

* server/mpm/prefork/prefork.c (child_main): If apr_pollset_poll()
  fails with EINTR and die_now has been set (indicating a graceful
  stop/restart), terminate the child quickly rather than re-entering
  poll().

Submitted by: jorton
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@662014 13f79535-47bb-0310-9956-ffa450edef68