bus: 'method_return' for responding to method-calls
bus: 'method_return' for responding to method-calls

Change-Id: Id959e500f3cba7f6e3b28c572ead95879bce6275
Signed-off-by: Patrick Williams <cbb7353e6d953ef360baf960c122346276c6e320@stwcx.xyz>

openbmc/sdbusplus,openbmc/sdbusplus,openbmc/sdbusplus,openbmc/sdbusplus