f2fs: support inode checksum

This patch adds to support inode checksum in f2fs.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix verification flow]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 50f1766..2a0c453 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -240,6 +240,7 @@
 			__le16 i_extra_isize;	/* extra inode attribute size */
 			__le16 i_padding;	/* padding */
 			__le32 i_projid;	/* project id */
+			__le32 i_inode_checksum;/* inode meta checksum */
 			__le32 i_extra_end[0];	/* for attribute size calculation */
 		};
 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */