xpipe: introduce (saves ~170 bytes)
udhcp/signalpipe.c: use pipe instead of socketpair.

diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index 39929fc..4b94aa2 100644
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -184,7 +184,7 @@
 		warnx("log must have at least seven characters");
 		return 0;
 	}
-	if (pipe(logpipe) == -1) {
+	if (pipe(logpipe)) {
 		warnx("cannot create pipe for log");
 		return -1;
 	}