asus-wmi: fix error handling in store_sys_wmi()

The asus_wmi_get_devstate_simple() returns 0-1 on success.  In theory
according to static checkers, it can return either -EIO or -ENODEV on
failure.  Currently the error handling code only handles -ENODEV and
-EIO is treated as success.  Let's make it handle the -EIO error as
well.

It's possible that it can't actually return -EIO and this patch is not
needed but in that case this patch is harmless and silences a static
checker warning so it's still worth it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>