xhci: fix possible memleak on setup address fails.

Xhci re-enables a slot on transaction error in set_address using
xhci_disable_slot() + xhci_alloc_dev().

But in this case, xhci_alloc_dev() creates debugfs entries upon an
existing device without cleaning up old entries, thus memory leaks.

So this patch simply moves calling xhci_debugfs_free_dev() from
xhci_free_dev() to xhci_disable_slot().

[added "possible" to header as this is about failure codepath -Mathias]
Signed-off-by: Ikjoon Jang <ikjn@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/1567172356-12915-5-git-send-email-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>