Add trailing slash for consistency (#17965)

<input type="text" name="SearchString">
=>
<input type="text" name="SearchString" />

Author: Brianmanden

aspnetcore/tutorials/first-mvc-app/start-mvc/sample/MvcMovie22/Views/Movies/IndexGet.cshtml

@@ -11,7 +11,7 @@
 </p>
 <form asp-controller="Movies" asp-action="Index" method="get">
     <p>
-        Title: <input type="text" name="SearchString">
+        Title: <input type="text" name="SearchString" />
         <input type="submit" value="Filter" />
     </p>
 </form>