Swift: Address further review comments.

Author: geoffw0

swift/ql/src/queries/Security/CWE-135/StringLengthConflation.ql

@@ -61,14 +61,8 @@ class StringLengthConflationConfiguration extends DataFlow::Configuration {
       ) and
       c.getName() = className and
       c.getAMember() = f and // TODO: will this even work if its defined in a parent class?
-      call.getFunction().(ApplyExpr).getFunction().(DeclRefExpr).getDecl() = f and
-      call.getFunction()
-          .(ApplyExpr)
-          .getFunction()
-          .(DeclRefExpr)
-          .getDecl()
-          .(AbstractFunctionDecl)
-          .getName() = methodName and
+      call.getFunction().(ApplyExpr).getStaticTarget() = f and
+      f.(AbstractFunctionDecl).getName() = methodName and
       f.getParam(arg).getName() = paramName and
       call.getArgument(arg).getExpr() = node.asExpr() and
       flowstate = "String" // `String` length flowing into `NSString`