Staging: quickstart: free after input_unregister_device()

input_unregister_device() releases "quickstart_input" so the
input_free_device() is a double free.  Also I noticed that there is a
memory leak if the call to input_register_device() fails.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>