move variant to std namespace

sdbusplus::message::variant_ns has been std for a while now. This moves
ipmid away from sdbusplus::message::variant_ns to directly use
std::variant.

Tested-by: built, compiles, and runs the same as before.

Change-Id: I8caa945f31c926c2721319f001b9d7f83fd3f1b7
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/read_fru_data.cpp b/read_fru_data.cpp
index 1f99e20..1a1949d 100644
--- a/read_fru_data.cpp
+++ b/read_fru_data.cpp
@@ -17,8 +17,6 @@
 namespace fru
 {
 
-namespace variant_ns = sdbusplus::message::variant_ns;
-
 using namespace phosphor::logging;
 using InternalFailure =
     sdbusplus::xyz::openbmc_project::Common::Error::InternalFailure;
@@ -140,9 +138,8 @@
                 if (iter != allProp.end())
                 {
                     data[properties.second.section].emplace(
-                        properties.first,
-                        std::move(variant_ns::get<std::string>(
-                            allProp[properties.first])));
+                        properties.first, std::move(std::get<std::string>(
+                                              allProp[properties.first])));
                 }
             }
         }