Fix ZERO_OR_NULL_PTR(ZERO_SIZE_PTR)

The comparison with ZERO_SIZE_PTR in ZERO_OR_NULL_PTR() needs to be <=
(not just <) so that ZERO_OR_NULL_PTR(ZERO_SIZE_PTR) is 1.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
[ Duh!  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/slab.h

@@ -40,7 +40,7 @@
  */
 #define ZERO_SIZE_PTR ((void *)16)
 
-#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) < \
+#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
 				(unsigned long)ZERO_SIZE_PTR)
 
 /*