patch 9.0.0152: warning for unused argument in small build

Problem:    Warning for unused argument in small build.
Solution:   Add "UNUSED".
diff --git a/src/version.c b/src/version.c
index 1e37a8e..feb3c4a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    152,
+/**/
     151,
 /**/
     150,