C++: Address review comments.

cpp/ql/src/Diagnostics/FailedExtractions.qll

@@ -84,10 +84,7 @@ class ExtractionUnrecoverableError extends ExtractionError, TCompilationFailed {
     result = "Unrecoverable extraction error while compiling " + f.toString()
   }
 
-  override string getErrorMessage() {
-    result =
-      "Unrecoverable compilation failure; check logs/build-tracer.log in the database directory for more information."
-  }
+  override string getErrorMessage() { result = "unrecoverable compilation failure." }
 
   override File getFile() { result = f }
 

cpp/ql/src/Diagnostics/FailedInvocations.ql

@@ -1,8 +1,8 @@
 /**
- * @name Aborted extractor invocations
+ * @name Failed extractor invocations
  * @description Gives the command line of compilations for which extraction did not run to completion.
  * @kind diagnostic
- * @id cpp/diagnostics/aborted-extractions
+ * @id cpp/diagnostics/failed-extractor-invocations
  */
 
 import cpp