Kotlin: Apply review feedback

Author: igfoo

java/ql/lib/semmle/code/java/ControlFlowGraph.qll

@@ -623,8 +623,6 @@ private module ControlFlowGraphImpl {
     or
     result = first(n.(InstanceOfExpr).getExpr())
     or
-    result = first(n.(NotInstanceOfExpr).getExpr())
-    or
     result = first(n.(SynchronizedStmt).getExpr())
     or
     result = n and

java/ql/lib/semmle/code/java/Expr.qll

@@ -2357,7 +2357,7 @@ class Argument extends Expr {
       tgt.getParameter(varargsParamPos).isVarargs() and
       arrayindex = pos - varargsParamPos and
       arrayindex >= 0 and
-      arrayindex <= (call.getNumArgument() - tgt.getNumberOfParameters())
+      arrayindex <= call.getNumArgument() - tgt.getNumberOfParameters()
     )
   }
 }