[PATCH] mm: try_to_unmap() is now void

[Randy Dunlap]

Fix the "CONFIG_MMU is not set" case of converting
try_to_unmap() from bool to void.

In file included from ../mm/vmscan.c:33:
../mm/vmscan.c: In function 'shrink_page_list':
../include/linux/rmap.h:294:34: warning: statement with no effect [-Wunused-value]
  294 | #define try_to_unmap(page, refs) false
      |                                  ^~~~~
../mm/vmscan.c:1508:4: note: in expansion of macro 'try_to_unmap'
 1508 |    try_to_unmap(page, flags);
      |    ^~~~~~~~~~~~

Fixes: 1fb08ac63bee ("mm: rmap: make try_to_unmap() void function")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
 include/linux/rmap.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210701.orig/include/linux/rmap.h
+++ linux-next-20210701/include/linux/rmap.h
@@ -291,7 +291,7 @@ static inline int page_referenced(struct
 	return 0;
 }
 
-#define try_to_unmap(page, refs) false
+#define try_to_unmap(page, refs) do {} while (0)
 
 static inline int page_mkclean(struct page *page)
 {