HID: lenovo-tpkbd: validate output report details

A HID device could send a malicious output report that would cause the
lenovo-tpkbd HID driver to write just beyond the output report allocation
during initialization, causing a heap overflow:

[   76.109807] usb 1-1: New USB device found, idVendor=17ef, idProduct=6009
...
[   80.462540] BUG kmalloc-192 (Tainted: G        W   ): Redzone overwritten

CVE-2013-2894

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>