Minor tweak to packaging tests.

When an option is changed on a command object, calling ensure_finalized
for a second time will not run finalize_options again, because
ensure_finalized is a no-op the second time.  By resetting the finalized
attribute, we can be sure that whatever computation takes place in
finalize_options will happen again.

(In test_command_clean, I removed two lines that were a no-op.)

Lib/packaging/tests/test_command_install_data.py

@@ -62,6 +62,7 @@ class InstallDataTestCase(support.TempdirManager,
 
         # let's try with warn_dir one
         cmd.warn_dir = True
+        cmd.finalized = False
         cmd.ensure_finalized()
         cmd.run()
 
@@ -80,6 +81,7 @@ class InstallDataTestCase(support.TempdirManager,
 
         cmd.data_files = {one: '{inst}/one', two: '{inst2}/two',
                           three: '{inst3}/three'}
+        cmd.finalized = False
         cmd.ensure_finalized()
         cmd.run()