8343482: Remove unnecessary @SuppressWarnings annotations (net)

Reviewed-by: dfuchs

src/java.base/share/classes/java/net/Socket.java

@@ -2057,7 +2057,6 @@ public class Socket implements java.io.Closeable {
      *
      * @since 9
      */
-    @SuppressWarnings("unchecked")
     public <T> T getOption(SocketOption<T> name) throws IOException {
         Objects.requireNonNull(name);
         if (isClosed())