Delegate invocations with check for null replaced with ?. operator

Source commit: 6541164eb2276378c284d70c6b5186251220eb4b

dotnet/Session.cs

@@ -1796,10 +1796,7 @@ namespace WinSCP
         {
             Logger.WriteLine("FileTransferredEvent: [{0}]", args.FileName);
 
-            if (FileTransferred != null)
-            {
-                FileTransferred(this, args);
-            }
+            FileTransferred?.Invoke(this, args);
         }
 
         internal void RaiseFailed(SessionRemoteException e)
@@ -1850,10 +1847,7 @@ namespace WinSCP
         {
             Logger.WriteLine("Output: [{0}]", data);
 
-            if (OutputDataReceived != null)
-            {
-                OutputDataReceived(this, new OutputDataReceivedEventArgs(data, error));
-            }
+            OutputDataReceived?.Invoke(this, new OutputDataReceivedEventArgs(data, error));
         }
 
         internal void DispatchEvents(int interval)

dotnet/internal/ExeSessionProcess.cs

@@ -385,10 +385,7 @@ namespace WinSCP
                 _lastFromBeginning = message;
                 _logger.WriteLine("Buffered from-beginning message [{0}]", _lastFromBeginning);
 
-                if (OutputDataReceived != null)
-                {
-                    OutputDataReceived(this, null);
-                }
+                OutputDataReceived?.Invoke(this, null);
             }
             else
             {
@@ -419,10 +416,7 @@ namespace WinSCP
 
             for (int i = 0; i < lines.Length - 1; ++i)
             {
-                if (OutputDataReceived != null)
-                {
-                    OutputDataReceived(this, new OutputDataReceivedEventArgs(lines[i], error));
-                }
+                OutputDataReceived?.Invoke(this, new OutputDataReceivedEventArgs(lines[i], error));
             }
         }