replace sdbusplus::message::variant_ns with std

now that sdbusplus has fully moved to std::variant and sdbusplus's
variant is just an alias to std::variant, there is no need to use the
sdbusplus namespace anymore.

Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
Change-Id: Ifaa21f06ff73c4432260a8215bbbf7bb1e4357fe
diff --git a/src/smbiosmdrv2handler.cpp b/src/smbiosmdrv2handler.cpp
index a6807ab..f3c4275 100644
--- a/src/smbiosmdrv2handler.cpp
+++ b/src/smbiosmdrv2handler.cpp
@@ -36,8 +36,6 @@
 
 std::unique_ptr<MDRV2> mdrv2 = nullptr;
 
-namespace variant_ns = sdbusplus::message::variant_ns;
-
 static void register_netfn_smbiosmdrv2_functions() __attribute__((constructor));
 static sdbusplus::bus::bus bus(ipmid_get_sd_bus_connection());
 
@@ -307,7 +305,7 @@
             "Error getting DirEnries");
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
-    if (requestData->dirIndex > variant_ns::get<uint8_t>(value))
+    if (requestData->dirIndex > std::get<uint8_t>(value))
     {
         return IPMI_CC_PARM_OUT_OF_RANGE;
     }