Fix UnboundLocalError when wiping memory

Bug introduced April 2019 after version 2.2 stable
d5ab76f

Reported by Ub3rZ4cH

Closes #575

bleachbit/Memory.py

@@ -274,7 +274,7 @@ def wipe_swap_linux(devices, proc_swaps):
         raise RuntimeError('Cannot wipe swap while it is in use')
     for device in devices:
         # TRANSLATORS: The variable is a device like /dev/sda2
-        logger.info(_("Wiping the swap device %s.") % device)
+        logger.info(_("Wiping the swap device %s."), device)
         safety_limit_bytes = 29 * 1024 ** 3  # 29 gibibytes
         actual_size_bytes = get_swap_size_linux(device, proc_swaps)
         if actual_size_bytes > safety_limit_bytes: