tests: drop unused local variable assignments in linelog

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Differential Revision: https://phab.mercurial-scm.org/D7760

tests/test-linelog.py

@@ -172,7 +172,7 b' class linelogtests(unittest.TestCase):'
                 ll.replacelines_vec(rev, a1, a2, blines)
             else:
                 ll.replacelines(rev, a1, a2, b1, b2)
-            ar = ll.annotate(rev)
+            ll.annotate(rev)
             self.assertEqual(ll.annotateresult, lines)
         # Verify we can get back these states by annotating each rev
         for lines, rev, a1, a2, b1, b2, blines, usevec in _genedits(