Be more forgiving with relative paths in search dirs

If a search dir is relative and starts by '..', the current code is going
to crash. Instead, accept it without normalizing it.

Change-Id: I4c401cab1b95e60508e8c97341121954899ed7f9

reloc.ml

@@ -1203,7 +1203,11 @@ let normalize_path path =
   let rec loop acc path =
     match path with
     | "."  :: path -> loop acc path
-    | ".." :: path -> loop (List.tl acc) path
+    | ".." :: path -> begin
+        match acc with
+        | _ :: q -> loop q path
+        | [] -> loop [".."] path
+      end
     | elem :: path -> loop (elem :: acc) path
     | [] -> List.rev acc
   in