buildman: Put our local libraries first in the path

If patman is installed on the machine (e.g. in the standard dist-packages
directory), it will find libraries from there in preference to our local
libraries. Adjust the order of the path to ensure that local libraries are
found first.
Signed-off-by: NSimon Glass <sjg@chromium.org>

tools/buildman/buildman.py

@@ -15,7 +15,7 @@ import unittest
 
 # Bring in the patman libraries
 our_path = os.path.dirname(os.path.realpath(__file__))
-sys.path.append(os.path.join(our_path, '../patman'))
+sys.path.insert(1, os.path.join(our_path, '../patman'))
 
 # Our modules
 import board