mm: make swap token dummies static inlines

Make use of the compiler's typechecking on !CONFIG_SWAP as well.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/swap.h

@@ -419,10 +419,22 @@ static inline swp_entry_t get_swap_page(void)
 }
 
 /* linux/mm/thrash.c */
-#define put_swap_token(mm)	do { } while (0)
-#define grab_swap_token(mm)	do { } while (0)
-#define has_swap_token(mm)	0
-#define disable_swap_token()	do { } while (0)
+static inline void put_swap_token(struct mm_struct *mm)
+{
+}
+
+static inline void grab_swap_token(struct mm_struct *mm)
+{
+}
+
+static inline int has_swap_token(struct mm_struct *mm)
+{
+	return 0;
+}
+
+static inline void disable_swap_token(void)
+{
+}
 
 static inline void
 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)