C++: Suspicious pointer scaling: @precision medium

This query is not producing good enough results to justify `@precision
high`. It's fundamentally looking for a pattern that should correlate
with memory management errors, but it doesn't look for the errors
themselves.

cpp/ql/src/Security/CWE/CWE-468/IncorrectPointerScaling.ql

@@ -4,7 +4,7 @@
  *              can cause buffer overflow conditions.
  * @kind problem
  * @problem.severity warning
- * @precision high
+ * @precision medium
  * @id cpp/suspicious-pointer-scaling
  * @tags security
  *       external/cwe/cwe-468