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/user_channel/channel_mgmt.cpp b/user_channel/channel_mgmt.cpp
index fc2ca1b..14b350e 100644
--- a/user_channel/channel_mgmt.cpp
+++ b/user_channel/channel_mgmt.cpp
@@ -34,6 +34,7 @@
 namespace ipmi
 {
 
+namespace variant_ns = sdbusplus::message::variant_ns;
 using namespace phosphor::logging;
 
 static constexpr const char* channelAccessDefaultFilename =
@@ -198,7 +199,7 @@
         if (prop.first == privilegePropertyString)
         {
             propName = privilegePropertyString;
-            intfPrivStr = prop.second.get<std::string>();
+            intfPrivStr = variant_ns::get<std::string>(prop.second);
             break;
         }
     }
@@ -1347,9 +1348,9 @@
                                       entry("INTERFACE:%s", intfName.c_str()));
                     continue;
                 }
-                intfPrivStr = variant.get<std::string>();
+                intfPrivStr = variant_ns::get<std::string>(variant);
             }
-            catch (const mapbox::util::bad_variant_access& e)
+            catch (const variant_ns::bad_variant_access& e)
             {
                 log<level::DEBUG>(
                     "exception: Network interface does not exist");