Also use rmtree to remove tmpdir_factory
Also use rmtree to remove tmpdir_factory

Same as e2c345100152fc7f2638ec8c3fd117cb67959c26

pfmoore/pip,pradyunsg/pip,pypa/pip,xavfernandez/pip,sbidoul/pip,pypa/pip,sbidoul/pip,xavfernandez/pip,pfmoore/pip,pradyunsg/pip,xavfernandez/pip