(Azure CXP) Fixing MicrosoftDocs/azure-docs-pr#47106

Fixing Typo in the code sample to register a pnp device

Author: AshokPeddakotla-MSFT

articles/iot-pnp/concepts-developer-guide.md

@@ -169,7 +169,7 @@ interfaces[1] = deviceInfoInterfaceHandle;
 result = DigitalTwin_DeviceClient_RegisterInterfacesAsync(
     digitalTwinClientHandle, // The handle for the connection to Azure IoT
     "urn:example:Thermostat_T_1000:1",
-    interfaceHandleList, 2,
+    interfaces, 2,
     null, null);
 ```