Fix error messages from jit-stealth-lock when load-average returns nil.

 lisp/jit-lock.el (jit-lock-stealth-fontify): Be tolerant to nil being
 returned by load-average.

lisp/ChangeLog

+2014-11-04  Eli Zaretskii  <eliz@gnu.org>
+
+	* jit-lock.el (jit-lock-stealth-fontify): Be tolerant to nil being
+	returned by load-average.
+
 2014-11-04  Michael Albinus  <michael.albinus@gmx.de>
         * net/tramp-sh.el (tramp-do-copy-or-rename-file-via-buffer): Don't use

lisp/jit-lock.el

@@ -503,7 +503,10 @@ non-nil in a repeated invocation of this function."
 	  message-log-max
 	  start)
       (if (and jit-lock-stealth-load
-	       (> (car (load-average)) jit-lock-stealth-load))
+	       ;; load-average can return nil.  The w32 emulation does
+	       ;; that during the first few dozens of seconds after
+	       ;; startup.
+	       (> (or (car (load-average)) 0) jit-lock-stealth-load))
 	  ;; Wait a little if load is too high.
 	  (setq delay jit-lock-stealth-time)
 	(if (buffer-live-p buffer)