f2fs: use bool for booleans

Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 692f35f..9a09459 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -850,7 +850,7 @@
 	mutex_init(&sbi->writepages);
 	mutex_init(&sbi->cp_mutex);
 	mutex_init(&sbi->node_write);
-	sbi->por_doing = 0;
+	sbi->por_doing = false;
 	spin_lock_init(&sbi->stat_lock);
 	init_rwsem(&sbi->bio_sem);
 	init_rwsem(&sbi->cp_rwsem);