Update MemoryWebClient.cs

Author: westdavidr

clients/dotnet/WebClient/MemoryWebClient.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 
 using System;
 using System.Collections.Generic;
@@ -438,18 +438,16 @@ private async Task<string> ImportInternalAsync(
             // Add files to the form
             for (int i = 0; i < uploadRequest.Files.Count; i++)
             {
-                using Stream fileStream = uploadRequest.Files[i].FileContent;
-
-                if (fileStream.CanSeek && fileStream.Position > 0)
+                if (uploadRequest.Files[i].FileContent is { CanSeek: true, Position: > 0 })
                 {
-                    fileStream.Seek(0, SeekOrigin.Begin);
+                    uploadRequest.Files[i].FileContent.Seek(0, SeekOrigin.Begin);
                 }
 
                 string fileName = uploadRequest.Files[i].FileName;
                 byte[] bytes;
-                using (var binaryReader = new BinaryReader(fileStream))
+                using (var binaryReader = new BinaryReader(uploadRequest.Files[i].FileContent))
                 {
-                    bytes = binaryReader.ReadBytes((int)fileStream.Length);
+                    bytes = binaryReader.ReadBytes((int)uploadRequest.Files[i].FileContent.Length);
                 }
 
                 var fileContent = new ByteArrayContent(bytes, 0, bytes.Length);