libfdt: Fix bug in delete_and_next_node()

Test: T/H
Change-Id: I41ceb4abd79b2de2cdfbf0f2766499157fabe5e0
diff --git a/libs/libfdt/src/lib.rs b/libs/libfdt/src/lib.rs
index d1ab24e..58b4463 100644
--- a/libs/libfdt/src/lib.rs
+++ b/libs/libfdt/src/lib.rs
@@ -493,6 +493,7 @@
             let next_node = self.delete_and_next(Some(offset))?.unwrap();
             Ok(Some((next_node, depth)))
         } else {
+            self.delete_and_next(None)?;
             Ok(None)
         }
     }