[DIO]: Fix typo in dio_resource_len()

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/dio.h

@@ -254,7 +254,7 @@ static inline struct dio_driver *dio_dev_driver(const struct dio_dev *d)
 
 #define dio_resource_start(d) ((d)->resource.start)
 #define dio_resource_end(d)   ((d)->resource.end)
-#define dio_resource_len(d)   ((d)->resource.end-(z)->resource.start+1)
+#define dio_resource_len(d)   ((d)->resource.end-(d)->resource.start+1)
 #define dio_resource_flags(d) ((d)->resource.flags)
 
 #define dio_request_device(d, name) \