std::variant: Fix new instances of mapbox specific calls

Tested:
    Build and run through unit tests.

Change-Id: I87f2d5441b2f029e1e96ee1b46c4c760b0d82aac
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/apphandler.cpp b/apphandler.cpp
index bd4b5c3..bed16ca 100644
--- a/apphandler.cpp
+++ b/apphandler.cpp
@@ -429,7 +429,7 @@
             bus, acpiObject.second, acpiObject.first, acpi_state::acpiInterface,
             acpi_state::sysACPIProp);
         auto sysACPI = acpi_state::ACPIPowerState::convertACPIFromString(
-            sysACPIVal.get<std::string>());
+            variant_ns::get<std::string>(sysACPIVal));
         res->sysACPIState =
             static_cast<uint8_t>(acpi_state::dbusToIPMI.at(sysACPI));
 
@@ -437,7 +437,7 @@
             bus, acpiObject.second, acpiObject.first, acpi_state::acpiInterface,
             acpi_state::devACPIProp);
         auto devACPI = acpi_state::ACPIPowerState::convertACPIFromString(
-            devACPIVal.get<std::string>());
+            variant_ns::get<std::string>(devACPIVal));
         res->devACPIState =
             static_cast<uint8_t>(acpi_state::dbusToIPMI.at(devACPI));