LWIS: Fix wrong kfree causing kernel panic

This fixes use-after-free quickly. This remains failed device
in the global list, but will be freed lwis_driver_exit().

It'd be better to free the failed device right away, which is TODO.

Bug: 178751352
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Change-Id: I3a283947ae079f19a55f5199a6aacd67aa35e7eb