Defining error codes as enum

The error codes has been moved under enum because of following benefit.
As the number against error codes were not specifying anything. Overhead
of maintaining unique number for each error code goes away.

Change-Id: Id2133c85306c7b65bb3a0ac1d622dda813f2256b
Signed-off-by: Sunny Srivastava <sunnsr25@in.ibm.com>
diff --git a/vpd-manager/include/utility/vpd_specific_utility.hpp b/vpd-manager/include/utility/vpd_specific_utility.hpp
index e366963..d72b7f3 100644
--- a/vpd-manager/include/utility/vpd_specific_utility.hpp
+++ b/vpd-manager/include/utility/vpd_specific_utility.hpp
@@ -1125,10 +1125,9 @@
  */
 inline std::string getErrCodeMsg(const uint16_t& i_errCode)
 {
-    if (error_code::errorCodeMap.find(i_errCode) !=
-        error_code::errorCodeMap.end())
+    if (errorCodeMap.find(i_errCode) != errorCodeMap.end())
     {
-        return error_code::errorCodeMap.at(i_errCode);
+        return errorCodeMap.at(i_errCode);
     }
 
     return std::string{};