pylibfdt: Use local pylibfdt module

Some systems may have the Python libfdt.py library installed. Adjust the
tests to prepend the local libfdt path so that we test the local version
instead of the system version.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tests/pylibfdt_tests.py

@@ -53,7 +53,7 @@ import sys
 import types
 import unittest
 
-sys.path.append('../pylibfdt')
+sys.path.insert(0, '../pylibfdt')
 import libfdt
 from libfdt import FdtException, QUIET_NOTFOUND, QUIET_ALL
 
@@ -66,7 +66,7 @@ def get_err(err_code):
     Returns:
         String error code
     """
-    return 'pylibfdt error %d: %s' % (-err_code, libfdt.fdt_strerror(-err_code))
+    return 'pylibfdt error %d: %s' % (-err_code, libfdt.strerror(-err_code))
 
 def _ReadFdt(fname):
     """Read a device tree file into an Fdt object, ready for use