Update sample for append blob article

Author: pauljewellmsft

articles/storage/blobs/storage-blob-append.md

@@ -36,48 +36,34 @@ Use either of these methods to append data to that append blob:
 The maximum size in bytes of each append operation is defined by the [AppendBlobMaxAppendBlockBytes](/dotnet/api/azure.storage.blobs.specialized.appendblobclient.appendblobmaxappendblockbytes) property. The following example creates an append blob and appends log data to that blob. This example uses the [AppendBlobMaxAppendBlockBytes](/dotnet/api/azure.storage.blobs.specialized.appendblobclient.appendblobmaxappendblockbytes) property to determine whether multiple append operations are required.
 
 ```csharp
-public static async void AppendToBlob
-    (BlobContainerClient containerClient, MemoryStream logEntryStream, string LogBlobName)
+static async Task AppendToBlob(
+    BlobContainerClient containerClient,
+    MemoryStream logEntryStream,
+    string logBlobName)
 {
-    AppendBlobClient appendBlobClient = containerClient.GetAppendBlobClient(LogBlobName);
+    AppendBlobClient appendBlobClient = containerClient.GetAppendBlobClient(logBlobName);
 
-    appendBlobClient.CreateIfNotExists();
+    await appendBlobClient.CreateIfNotExistsAsync();
 
-        var maxBlockSize = appendBlobClient.AppendBlobMaxAppendBlockBytes;
-    
-        var buffer = new byte[maxBlockSize];
+    var maxBlockSize = appendBlobClient.AppendBlobMaxAppendBlockBytes;
 
     if (logEntryStream.Length <= maxBlockSize)
     {
-        appendBlobClient.AppendBlock(logEntryStream);
+        await appendBlobClient.AppendBlockAsync(logEntryStream);
     }
     else
     {
-        var bytesLeft = (logEntryStream.Length - logEntryStream.Position);
+        var bytesLeft = logEntryStream.Length;
 
         while (bytesLeft > 0)
         {
-            if (bytesLeft >= maxBlockSize)
-            {
-                buffer = new byte[maxBlockSize];
-                await logEntryStream.ReadAsync
-                    (buffer, 0, maxBlockSize);
-            }
-            else
-            {
-                buffer = new byte[bytesLeft];
-                await logEntryStream.ReadAsync
-                    (buffer, 0, Convert.ToInt32(bytesLeft));
-            }
-
-            appendBlobClient.AppendBlock(new MemoryStream(buffer));
-
-            bytesLeft = (logEntryStream.Length - logEntryStream.Position);
-
+            var blockSize = (int)Math.Min(bytesLeft, maxBlockSize);
+            var buffer = new byte[blockSize];
+            await logEntryStream.ReadAsync(buffer, 0, blockSize);
+            await appendBlobClient.AppendBlockAsync(new MemoryStream(buffer));
+            bytesLeft -= blockSize;
         }
-
     }
-
 }
 ```