Make it more explicit that jiffies are "unsigned long", but

that we for the initial value ctually want to check only
wrap-around in an "unsigned int". 

include/linux/time.h

@@ -31,7 +31,7 @@ struct timezone {
  * Have the 32 bit jiffies value wrap 5 minutes after boot
  * so jiffies wrap bugs show up earlier.
  */
-#define INITIAL_JIFFIES ((unsigned int) (-300*HZ))
+#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))
 
 /*
  * Change timeval to jiffies, trying to avoid the