f2fs: align data types between on-disk and in-memory block addresses

The on-disk block address is defined as __le32, but in-memory block address,
block_t, does as u64.

Let's synchronize them to 32 bits.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index df6fab8..383d5e3 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -20,8 +20,8 @@
 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
 
-#define NULL_ADDR		0x0U
-#define NEW_ADDR		-1U
+#define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
+#define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
 
 #define F2FS_ROOT_INO(sbi)	(sbi->root_ino_num)
 #define F2FS_NODE_INO(sbi)	(sbi->node_ino_num)