Prevent duplicate entries in callout list

If duplicates exist, only the highest priority callout will remain in
the list.

Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
Change-Id: Ibec768b22c944965460010be8867749a8c0f9044
diff --git a/analyzer/service_data.hpp b/analyzer/service_data.hpp
index ce9993e..ac90707 100644
--- a/analyzer/service_data.hpp
+++ b/analyzer/service_data.hpp
@@ -72,10 +72,7 @@
      * @brief Add callout information to the callout list.
      * @param The JSON object for this callout.
      */
-    void addCallout(const nlohmann::json& i_callout)
-    {
-        iv_calloutList.push_back(i_callout);
-    }
+    void addCallout(const nlohmann::json& i_callout);
 
     /**
      * @brief Add FFDC for a callout that would otherwise not be available in