installer: Clean up unattended preinstall drivers

Signed-off-by: Cole Robinson <crobinso@redhat.com>

virtinst/install/installer.py

@@ -234,8 +234,8 @@ class Installer(object):
                 guest.os.arch)
         drivers = unattended.download_drivers(drivers_location,
                 InstallerTreeMedia.make_scratchdir(guest), meter)
-        if drivers:
         injections.extend(drivers)
+        self._tmpfiles.extend([driverpair[0] for driverpair in drivers])
 
         iso = perform_cdrom_injections(injections,
                 InstallerTreeMedia.make_scratchdir(guest))

virtinst/install/unattended.py

@@ -376,9 +376,14 @@ def download_drivers(locations, scratchdir, meter):
 
     drivers = []
 
+    try:
         for location in locations:
             filename = location.rsplit('/', 1)[1]
             driver = fetcher.acquireFile(location)
             drivers.append((driver, filename))
+    except Exception:  # pragma: no cover
+        for driverpair in drivers:
+            os.unlink(driverpair[0])
+        raise
 
     return drivers