zram: use proper type to update max_used_pages

max_used_pages is defined as atomic_long_t so we need to use unsigned
long to keep temporary value for it rather than int which is smaller
than unsigned long in a 64 bit system.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/zram/zram_drv.c

@@ -528,7 +528,7 @@ out_cleanup:
 static inline void update_used_max(struct zram *zram,
 					const unsigned long pages)
 {
-	int old_max, cur_max;
+	unsigned long old_max, cur_max;
 
 	old_max = atomic_long_read(&zram->stats.max_used_pages);