Reuse Ping and Quit payload objects.

Author: bgrainger

src/MySqlConnector/Core/ServerSession.cs

@@ -197,7 +197,7 @@ public async Task DisposeAsync(IOBehavior ioBehavior, CancellationToken cancella
 					{
 						Log.Info("{0} sending QUIT command", m_logArguments);
 						m_payloadHandler.StartNewConversation();
-						await m_payloadHandler.WritePayloadAsync(QuitPayload.Create().ArraySegment, ioBehavior).ConfigureAwait(false);
+						await m_payloadHandler.WritePayloadAsync(QuitPayload.Instance.ArraySegment, ioBehavior).ConfigureAwait(false);
 					}
 					catch (IOException)
 					{
@@ -514,7 +514,7 @@ public async ValueTask<bool> TryPingAsync(IOBehavior ioBehavior, CancellationTok
 			try
 			{
 				Log.Debug("{0} pinging server", m_logArguments);
-				await SendAsync(PingPayload.Create(), ioBehavior, cancellationToken).ConfigureAwait(false);
+				await SendAsync(PingPayload.Instance, ioBehavior, cancellationToken).ConfigureAwait(false);
 				var payload = await ReceiveReplyAsync(ioBehavior, cancellationToken).ConfigureAwait(false);
 				OkPayload.Create(payload);
 				Log.Info("{0} successfully pinged server", m_logArguments);

src/MySqlConnector/Protocol/Payloads/PingPayload.cs

@@ -2,6 +2,6 @@ namespace MySqlConnector.Protocol.Payloads
 {
 	internal sealed class PingPayload
 	{
-		public static PayloadData Create() => new PayloadData(new[] { (byte) CommandKind.Ping });
+		public static PayloadData Instance { get; } = new PayloadData(new[] { (byte) CommandKind.Ping });
 	}
 }

src/MySqlConnector/Protocol/Payloads/QuitPayload.cs

@@ -2,6 +2,6 @@ namespace MySqlConnector.Protocol.Payloads
 {
 	internal sealed class QuitPayload
 	{
-		public static PayloadData Create() => new PayloadData(new[] { (byte) CommandKind.Quit });
+		public static PayloadData Instance { get; } = new PayloadData(new[] { (byte) CommandKind.Quit });
 	}
 }