GCC complains

diff -ur src/zgv_io.c src/zgv_io.c
--- src/zgv_io.c	2005-01-20 15:07:46.000000000 -0800
+++ src/zgv_io.c	2016-06-29 10:19:40.169897611 -0700
@@ -645,7 +645,7 @@
         case SDLK_INSERT:	return(RK_INSERT);
         case SDLK_DELETE:	return(RK_DELETE);
         case SDLK_RETURN:	return(RK_ENTER);
-        default:
+        default: ;
           /* stop complaints */
         }