ipmid: replace std::experimental::optional with std::optional

Now that the project is using c++17, std::optional can be used directly
instead of via the std::experimental way.

Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
Change-Id: I7087f58bd3d9fd90b8b31e6902554351a3db2d0f
2 files changed