[COIL][tlsdate] Change offensive wording in sigchld.c

While COIL guidelines don't explicitly discourage the offensive wording
in this file, the reason for this change is covered by the discussion
around the term `postmortem`.

BUG=None
TEST=trybots

Change-Id: I369df29c76f6dd41400f600718d7da70d35ddd09
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/tlsdate/+/2759700
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Tested-by: Andreea-Elena Costinas <acostinas@google.com>
Commit-Queue: Andreea-Elena Costinas <acostinas@google.com>
1 file changed