Reduce nesting in CheckMacrosPass.CheckForTemplateConstraints.

src/Generator/Passes/CheckMacrosPass.cs

@@ -221,8 +221,10 @@ namespace CppSharp.Passes
 
             var expansion = expansions.FirstOrDefault(
                 e => e.Text.StartsWith(Prefix + "_CONSTRAINT", StringComparison.Ordinal));
-            if (expansion != null)
-            {
+
+            if (expansion == null)
+                return;
+
             var args = GetArguments(expansion.Text);
             for (var i = 0; i < template.Parameters.Count && i < args.Length; ++i)
             {
@@ -231,7 +233,6 @@ namespace CppSharp.Passes
                     templateParam.Constraint = args[i];
             }
         }
-        }
 
         private static string[] GetArguments(string str)
         {