Pass full path of the XML in local_manifests to the parser

This fixes the following python error message if the
current working directory is not .repo/local_manifests:
IOError: [Errno 2] No such file or directory: 'local_manifest.xml'

Signed-off-by: Tobias Droste <tdroste87@gmail.com>
CC: David Pursehouse <david.pursehouse@sonymobile.com>
Change-Id: I4668dc04219b6233c7ff6ca3b4138bec9ee3529f

manifest_xml.py

@@ -346,7 +346,8 @@ class XmlManifest(object):
         for local_file in sorted(os.listdir(local_dir)):
           if local_file.endswith('.xml'):
             try:
-              nodes.append(self._ParseManifestXml(local_file, self.repodir))
+              local = os.path.join(local_dir, local_file)
+              nodes.append(self._ParseManifestXml(local, self.repodir))
             except ManifestParseError as e:
               print('%s' % str(e), file=sys.stderr)
       except OSError: