patch 8.1.2297: the ex_vimgrep() function is too long

Problem:    The ex_vimgrep() function is too long.
Solution:   Split it in three parts. (Yegappan Lakshmanan, closes #5211)
diff --git a/src/version.c b/src/version.c
index 314f164..4987b78 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2297,
+/**/
     2296,
 /**/
     2295,