IPMIFruArea: use default destructor

Use default destructor now that there isn't a raw pointer.

Change-Id: I3b28a99ca27a9e5dd15de9809e882cab02eedf75
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/fru_area.hpp b/fru_area.hpp
index 5294be2..abfa083 100644
--- a/fru_area.hpp
+++ b/fru_area.hpp
@@ -15,14 +15,12 @@
 {
   public:
     IPMIFruArea() = delete;
+    ~IPMIFruArea() = default;
 
     // constructor
     IPMIFruArea(const uint8_t fruID, const ipmi_fru_area_type type,
                 bool bmcOnlyFru = false);
 
-    // Destructor
-    virtual ~IPMIFruArea();
-
     // Sets the present bit
     inline void setPresent(const bool present)
     {