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/smbiosmdrv2.cpp b/src/smbiosmdrv2.cpp
index 1b237fe..bce8929 100644
--- a/src/smbiosmdrv2.cpp
+++ b/src/smbiosmdrv2.cpp
@@ -217,8 +217,7 @@
             "Error getting DirEnries");
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
-    if (requestData->dirIndex >
-        sdbusplus::message::variant_ns::get<uint8_t>(value))
+    if (requestData->dirIndex > std::get<uint8_t>(value))
     {
         return IPMI_CC_PARM_OUT_OF_RANGE;
     }