Error handling for executeCmd API

This commit updates executeCmd API to set error code in case of error.
This helps the caller of API to take action based on the error code
returned from the API.

Change-Id: Ie5b7804f5d486a278765d460eabaef0bd46d555e
Signed-off-by: Rekha Aparna <vrekhaaparna@ibm.com>
diff --git a/vpd-manager/include/error_codes.hpp b/vpd-manager/include/error_codes.hpp
index 0665709..e404cf5 100644
--- a/vpd-manager/include/error_codes.hpp
+++ b/vpd-manager/include/error_codes.hpp
@@ -33,6 +33,7 @@
     ERROR_PROCESSING_SYSTEM_CMD,
     STANDARD_EXCEPTION,
     DBUS_FAILURE,
+    POPEN_FAILED,
 
     // VPD specific errors
     UNSUPPORTED_VPD_TYPE,
@@ -84,5 +85,6 @@
      "Failed to detect location code type"},
     {error_code::DBUS_FAILURE, "Dbus call failed"},
     {error_code::RECEIVED_INVALID_KWD_TYPE_FROM_DBUS,
-     "Received invalid keyword data type from DBus."}};
+     "Received invalid keyword data type from DBus."},
+    {error_code::POPEN_FAILED, "popen failed"}};
 } // namespace vpd