udf: Init/maintain file entry checkpoint field

In accordance with ECMA 1.67 Part 4, 14.9.15, the checkpoint field
should be initialized to 1 at creation. (Zero is *not* a valid value.)

Signed-off-by: Steven P. Nickel <snickel@focusinfo.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h
index d1bd31e..bb8309d 100644
--- a/fs/udf/udf_i.h
+++ b/fs/udf/udf_i.h
@@ -23,6 +23,7 @@
 	__u64			i_lenExtents;
 	__u32			i_next_alloc_block;
 	__u32			i_next_alloc_goal;
+	__u32			i_checkpoint;
 	unsigned		i_alloc_type : 3;
 	unsigned		i_efe : 1;	/* extendedFileEntry */
 	unsigned		i_use : 1;	/* unallocSpaceEntry */