LWIS: Return error in lwis_ioreg_io_entry_rw()

lwis_ioreg_io_entry_rw() does not return correct error code
when error.

Bug: 192904623
Bug: 190212527
Bug: 191114282
Test: GCA, CTS
Signed-off-by: Holmes Chou <holmeschou@google.com>
Change-Id: I333a39ee91cc8d92c5dfeb56a753afb64a730fac