Input: psmouse - fix potential memory leak in psmouse_connect()

If we successfully call input_register_device() in psmouse_connect()
but sysfs_create_group() fails, we'll enter the error path without
ever having called input_unregister_device() potentially leaking
memory.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>