Use ArgumentNullException.ThrowIfNull helper method

Did a simple search/replace on the whole repo (except the RSSDP project)
This reduces LOC and should improve performance (methods containing a throw statement don't get inlined)

```
if \((\w+) == null\)
\s+\{
\s+throw new ArgumentNullException\((.*)\);
\s+\}
```

```
ArgumentNullException.ThrowIfNull($1);
```

1 files changed, 2 insertions, 8 deletions

diff --git a/Emby.Dlna/ContentDirectory/ControlHandler.cs b/Emby.Dlna/ContentDirectory/ControlHandler.cs
index 57170bb31..fc69960fd 100644
--- a/Emby.Dlna/ContentDirectory/ControlHandler.cs
+++ b/Emby.Dlna/ContentDirectory/ControlHandler.cs
@@ -114,15 +114,9 @@ namespace Emby.Dlna.ContentDirectory
         /// <inheritdoc />
         protected override void WriteResult(string methodName, IReadOnlyDictionary<string, string> methodParams, XmlWriter xmlWriter)
         {
-            if (xmlWriter == null)
-            {
-                throw new ArgumentNullException(nameof(xmlWriter));
-            }
+            ArgumentNullException.ThrowIfNull(xmlWriter);
 
-            if (methodParams == null)
-            {
-                throw new ArgumentNullException(nameof(methodParams));
-            }
+            ArgumentNullException.ThrowIfNull(methodParams);
 
             const string DeviceId = "test";