Merge pull request #6264 from hpcc-systems/revert-6232-HPCC-11901-fix

Revert "HPCC-11901 CSV auto discovery generates wrong field names if rec...

Reviewed-By: Attila Vamos <attila.vamos@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>

dali/ft/daftformat.cpp

@@ -613,7 +613,7 @@ void CCsvPartitioner::storeFieldName(const char * start, unsigned len)
     }
     else
     {
-        recordStructure.set("field");
+        recordStructure.append("field");
         recordStructure.append(fieldCount);
     }
     recordStructure.append(";\n");