UBIFS: separate debugging fields out

Introduce a new data structure which contains all debugging
stuff inside. This is cleaner than having debugging stuff
directly in 'c'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
index 9bd5a43..9e6f403 100644
--- a/fs/ubifs/orphan.c
+++ b/fs/ubifs/orphan.c
@@ -899,7 +899,7 @@
 	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
 		struct ubifs_scan_leb *sleb;
 
-		sleb = ubifs_scan(c, lnum, 0, c->dbg_buf);
+		sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
 		if (IS_ERR(sleb)) {
 			err = PTR_ERR(sleb);
 			break;