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_cmdline/test_help.py

@@ -141,6 +141,6 @@ def test_multiline_description():
     assert '\n\n' in unicode(api.Command.trust_add.doc).strip()
 
     with CLITestContext(exception=SystemExit) as help_ctx:
-        return_value = api.Backend.cli.run(['trust-add', '-h'])
+        api.Backend.cli.run(['trust-add', '-h'])
 
     assert unicode(api.Command.trust_add.doc).strip() in help_ctx.stdout

ipatests/test_cmdline/test_ipagetkeytab.py

@@ -114,7 +114,7 @@ class test_ipagetkeytab(cmdline_test):
                 self.keytabname)
             assert expected in result.error_output, (
                 'Success message not in output:\n%s' % result.error_output)
-        except ipautil.CalledProcessError as e:
+        except ipautil.CalledProcessError:
             assert (False)
 
     def test_3_use(self):