patch 8.0.0326: packadd test uses wrong directory name

Problem:    Packadd test uses wrong directory name.
Solution:   Use the variable name value. (Hirohito Higashi)
diff --git a/src/version.c b/src/version.c
index 49b03ca..381a6d5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    326,
+/**/
     325,
 /**/
     324,