Fix JS_GetArrayElement to not return an empty handle on success

fpdfsdk/src/jsapi/fxjs_v8.cpp

Index: fpdfsdk/src/jsapi/fxjs_v8.cpp
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index f2f2e55898f018f56186ad2d086fa4022948ca31..1dd479aec624e686927b758f9e058511bb6f1c50 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -743,7 +743,7 @@ v8::Local<v8::Value> JS_GetArrayElement(IJS_Runtime* pJSRuntime,
   if (pArray.IsEmpty())
     return v8::Local<v8::Value>();
   v8::Local<v8::Value> val;
-  if (pArray->Get(pJSRuntime->GetCurrentContext(), index).ToLocal(&val))
+  if (!pArray->Get(pJSRuntime->GetCurrentContext(), index).ToLocal(&val))
     return v8::Local<v8::Value>();
   return val;
 }