There are no overloads of this virtual function, nor are there any callers of it. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215705 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Analysis/Analyses/ThreadSafety.h

@@ -188,9 +188,6 @@ public:
   /// Called by the analysis when finishing analysis of a function.
   virtual void leaveFunction(const FunctionDecl *FD) {}
 
-  /// Return the number of errors found within this function so far.
-  virtual int numErrors() { return 0; }
-
   bool issueBetaWarnings() { return IssueBetaWarnings; }
   void setIssueBetaWarnings(bool b) { IssueBetaWarnings = b; }