cbfs: Rename checksum to attributes_offset

It seems that this field has been renamed in later version of coreboot.
Update it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c
index 7b2513c..af4d3c5 100644
--- a/fs/cbfs/cbfs.c
+++ b/fs/cbfs/cbfs.c
@@ -55,7 +55,7 @@
 	memcpy(&dest->magic, &src->magic, sizeof(dest->magic));
 	dest->len = be32_to_cpu(src->len);
 	dest->type = be32_to_cpu(src->type);
-	dest->checksum = be32_to_cpu(src->checksum);
+	dest->attributes_offset = be32_to_cpu(src->attributes_offset);
 	dest->offset = be32_to_cpu(src->offset);
 }
 
@@ -108,7 +108,7 @@
 		newNode->name = (char *)fileHeader +
 				sizeof(struct cbfs_fileheader);
 		newNode->name_length = name_len;
-		newNode->checksum = header.checksum;
+		newNode->attributes_offset = header.attributes_offset;
 
 		step = header.len;
 		if (step % align)