toshiba_acpi: Change HCI/SCI functions return code type

Currently the HCI/SCI read/write functions are returning
the status of the ACPI call and also assigning the
returned value of the HCI/SCI function, however, only
the HCI/SCI status is being checked.

This patch changes such functions, returning the value
of the HCI/SCI function instead of the ACPI call status,
eliminating one parameter, and returning something
useful that indeed is being checked.

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>