staging: cptm1217: don't call input_free_device() after input_unregister_device()

input_free_device() should only be used if input_register_device()
was not called yet or if it failed. Once device was unregistered
use input_unregister_device() and memory will be freed once last
reference to the device is dropped.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>