patch 8.1.2270: "gf" is not tested in Visual mode

Problem:    "gf" is not tested in Visual mode.
Solution:   Add Visual mode test and test errors. (Dominique Pelle,
            closes #5197)
diff --git a/src/version.c b/src/version.c
index 541b2ad..bd442f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2270,
+/**/
     2269,
 /**/
     2268,