Remove unused variables in tests

This commit removes or marks unused variables as "expected to be unused"
by using '_' prefix.

Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

ipatests/test_ipapython/test_cookie.py

@@ -279,7 +279,7 @@ class TestInvalidAttributes(unittest.TestCase):
         # Invalid Max-Age
         s = 'color=blue; Max-Age=over-the-hill'
         with self.assertRaises(ValueError):
-            cookies = Cookie.parse(s)
+            Cookie.parse(s)
 
         cookie = Cookie('color', 'blue')
         with self.assertRaises(ValueError):
@@ -288,7 +288,7 @@ class TestInvalidAttributes(unittest.TestCase):
         # Invalid Expires
         s = 'color=blue; Expires=Sun, 06 Xxx 1994 08:49:37 GMT'
         with self.assertRaises(ValueError):
-            cookies = Cookie.parse(s)
+            Cookie.parse(s)
 
         cookie = Cookie('color', 'blue')
         with self.assertRaises(ValueError):

ipatests/test_ipapython/test_dn.py

@@ -933,7 +933,7 @@ class TestDN(unittest.TestCase):
             dn3[1.0]  # pylint: disable=pointless-statement
 
     def test_assignments(self):
-        dn = dn2 = DN('t=0,t=1,t=2,t=3,t=4,t=5,t=6,t=7,t=8,t=9')
+        dn = DN('t=0,t=1,t=2,t=3,t=4,t=5,t=6,t=7,t=8,t=9')
         with self.assertRaises(TypeError):
             dn[0] = RDN('t=a')
         with self.assertRaises(TypeError):

ipatests/test_ipapython/test_ipautil.py

@@ -183,7 +183,6 @@ class TestCIDict(object):
             self.cidict.keys(), self.cidict.values()))
 
     def test_iter(self):
-        items = []
         assert list(self.cidict) == list(self.cidict.keys())
         assert sorted(self.cidict) == sorted(['Key1', 'key2', 'KEY3'])
 

ipatests/test_ipapython/test_keyring.py

@@ -111,7 +111,7 @@ class test_keyring(object):
         """
         Read a non-existent key
         """
-        result = kernel_keyring.read_key(TEST_KEY)
+        kernel_keyring.read_key(TEST_KEY)
 
     def test_06(self):
         """