Fix a couple of potential graceful restart bugs noted by Dean: EINTR was

never dealt with in the code to write to the pipe of death, and in
pathological cases where the number of processes is greater than
PIPE_BUF, we could end up only killing some processes.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@83563 13f79535-47bb-0310-9956-ffa450edef68