Update swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

Co-authored-by: Mathias Vorreiter Pedersen <mathiasvp@github.com>

Author: geoffw0

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

@@ -155,16 +155,14 @@ private module Cached {
     or
     // flow through nil-coalescing operator `??`
     exists(BinaryExpr nco |
-      nco.getFunction().(DeclRefExpr).getDecl().(FreeFunctionDecl).getName() = "??(_:_:)" and
-      (
-        // value argument
-        nodeFrom.asExpr() = nco.getAnOperand()
-        or
-        // unpack closure (the second argument is typically an `AutoClosureExpr` argument)
-        nodeFrom.asExpr() =
-          nco.getAnOperand().(AbstractClosureExpr).getBody().getAnElement().(ReturnStmt).getResult()
-      ) and
+      nco.getStaticTarget().(FreeFunctionDecl).getName() = "??(_:_:)" and
       nodeTo.asExpr() = nco
+    |
+      // value argument
+      nodeFrom.asExpr() = nco.getAnOperand()
+      or
+      // unpack closure (the second argument is typically an `AutoClosureExpr` argument)
+      nodeFrom.asExpr() = nco.getAnOperand().(AutoClosureExpr).getReturn().getResult()
     )
     or
     // flow through ternary operator `? :`