mm/vmscan.c: make may_enter_fs bool in shrink_page_list()

This gives some size improvement:

$size mm/vmscan.o (before)
   text	   data	    bss	    dec	    hex	filename
  53670	  24123	     12	  77805	  12fed	mm/vmscan.o

$size mm/vmscan.o (after)
   text	   data	    bss	    dec	    hex	filename
  53648	  24123	     12	  77783	  12fd7	mm/vmscan.o
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/Message-ID:
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c

@@ -1084,9 +1084,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 	while (!list_empty(page_list)) {
 		struct address_space *mapping;
 		struct page *page;
-		int may_enter_fs;
 		enum page_references references = PAGEREF_RECLAIM;
-		bool dirty, writeback;
+		bool dirty, writeback, may_enter_fs;
 		unsigned int nr_pages;
 
 		cond_resched();
@@ -1267,7 +1266,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 						goto activate_locked_split;
 				}
 
-				may_enter_fs = 1;
+				may_enter_fs = true;
 
 				/* Adding to swap updated mapping */
 				mapping = page_mapping(page);