driver core: bus: Return -EIO instead of 0 when show/store invalid bus attribute

Return -EIO instead of 0 for below erroneous bus attribute operations:
 - read a bus attribute without show().
 - write a bus attribute without store().

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240724-bus_fix-v2-1-5adbafc698fb@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>