Fix the namedtuple's name.

debexpo/plugins/lintian.py

@@ -52,7 +52,7 @@ from debexpo.model import meta
 
 log = logging.getLogger(__name__)
 
-LintianSeverity = namedtuple('SeverityTuple',
+LintianSeverity = namedtuple('LintianSeverity',
                              ['str', 'int', 'plugin_severity'])
 severities = {
     'E': LintianSeverity('Package has lintian errors', 5,