sleep: don't return errno from main()

[Philip Guenther]

As a general rule, programs should not use errno values as an exit status.

Compare "sleep 100000001" w/ and w/o this diff.

ok?

Index: sleep.c
===================================================================
RCS file: /data/src/openbsd/src/bin/sleep/sleep.c,v
retrieving revision 1.23
diff -u -p -r1.23 sleep.c
--- sleep.c     9 Oct 2015 01:37:06 -0000       1.23
+++ sleep.c     10 Oct 2015 23:19:03 -0000
@@ -107,7 +107,7 @@ main(int argc, char *argv[])
 
        if ((secs > 0) || (nsecs > 0))
                if (nanosleep(&rqtp, NULL))
-                       return (errno);
+                       err(1, NULL);
        return (0);
 }