syslog called werrstr with the error previously saved, but werrstr's first
argument is a format, and if the error contained % it can and does cause crashes.
just call errstr again to swap it back. it's needed in case the syslog format refers to %r.
also call errstr at the right point, after the call to sysname(), which does a system call.

Reference: /n/sources/patch/applied/syslog-errstr
Date: Sun Jan 20 10:25:51 CET 2013
Signed-off-by: charles.forsyth@gmail.com

--- /sys/src/libc/9sys/syslog.c	Sun Jan 20 10:25:22 2013
+++ /sys/src/libc/9sys/syslog.c	Sun Jan 20 10:25:19 2013
@@ -93,11 +93,11 @@
 	}
 
 	ctim = ctime(time(0));
-	werrstr(err);
 	p = buf + snprint(buf, sizeof(buf)-1, "%s ", sysname());
 	strncpy(p, ctim+4, 15);
 	p += 15;
 	*p++ = ' ';
+	errstr(err, sizeof err);
 	va_start(arg, fmt);
 	p = vseprint(p, buf+sizeof(buf)-1, fmt, arg);
 	va_end(arg);