fixed hipFunction memory management

Change-Id: I7ebb323419bcd220ebd6466a8eb38e7bfdb1520a

src/trace_helper.h

@@ -72,17 +72,6 @@ inline std::string ToString(hipEvent_t v)
     return ss.str();
 };
 
-//  hipEvent_t specialization. TODO - maybe add an event ID for debug?
-template <>
-inline std::string ToString(hipFunction_t v)
-{
-    std::ostringstream ss;
-    ss << "0x" << std::hex << v._object;
-    return ss.str();
-};
-
-
-
 //  hipStream_t
 template <>
 inline std::string ToString(hipStream_t v)