Code example should not use APM

The code example for this page uses the APM (as can be seen from it calling `EndRead`). Since APM is not recommended anymore, I think examples should not use it (unless they have to).

Fixing this would involve changing this page, the larger example in the `FileStream` constructor and also other pages that use this example, if any.

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#### Document Details

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* ID: e7cc1aa5-01fa-daaf-29e9-629c764c06c0
* Version Independent ID: 89fad939-286b-4cd6-dfb3-5f3cc1c893de
* Content: [FileStream.Name Property (System.IO)](https://docs.microsoft.com/en-us/dotnet/api/system.io.filestream.name?redirectedfrom=MSDN&view=netframework-4.7.2#System_IO_FileStream_Name)
* Content Source: [xml/System.IO/FileStream.xml](https://github.com/dotnet/dotnet-api-docs/blob/master/xml/System.IO/FileStream.xml)
* Product: **dotnet-api**
* GitHub Login: @dotnet-bot
* Microsoft Alias: **dotnetcontent**