Bug fix:

. check proper error variable when handling errors from ap_write(pipe_of_death)
. log proper error variable after ap_poll() failure
. ditto for ap_create_pipe() failures
. ditto for ap_set_pipe_timeout() failures
Stylistic change:
. pass 0 instead of errno to ap_log_error when APLOG_NOERRNO is specified


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85684 13f79535-47bb-0310-9956-ffa450edef68