rawArgument in GetArgumentList cant be null (#5056)

since it is always guarded in the preceding code

Author: SimonCropp

src/vstest.console/Processors/Utilities/ArgumentProcessorUtilities.cs

@@ -18,12 +18,19 @@ internal class ArgumentProcessorUtilities
     /// <param name="argumentSeparator">Argument separator.</param>
     /// <param name="exceptionMessage">Exception Message.</param>
     /// <returns>Argument list.</returns>
-    public static string[] GetArgumentList(string? rawArgument, char[] argumentSeparator, string exceptionMessage)
+    public static string[] GetArgumentList(string rawArgument, char[] argumentSeparator, string exceptionMessage)
     {
-        var argumentList = rawArgument?.Split(argumentSeparator, StringSplitOptions.RemoveEmptyEntries);
+        var argumentList = rawArgument.Split(argumentSeparator, StringSplitOptions.RemoveEmptyEntries);
 
         // Throw error in case of invalid argument.
-        return argumentList == null || argumentList.Length <= 0 ? throw new CommandLineException(exceptionMessage) : argumentList;
+        if (argumentList.Length <= 0)
+        {
+            throw new CommandLineException(exceptionMessage);
+        }
+        else
+        {
+            return argumentList;
+        }
     }
 
     /// <summary>