Revert "buildman: Correct CROSS_COMPILE output for sandbox"

This reverts commit bd0a548ad4a155fec29473d4cc8e135832926973.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/toolchain.py b/tools/buildman/toolchain.py
index 8f9130b..688f2e2 100644
--- a/tools/buildman/toolchain.py
+++ b/tools/buildman/toolchain.py
@@ -156,8 +156,9 @@
         Returns:
             Value of that environment variable or arguments
         """
+        wrapper = self.GetWrapper()
         if which == VAR_CROSS_COMPILE:
-            return self.GetWrapper() + self.cross
+            return wrapper + os.path.join(self.path, self.cross)
         elif which == VAR_PATH:
             return self.path
         elif which == VAR_ARCH: