patch 9.1.0615: Unnecessary STRLEN() in make_percent_swname()

Problem:  Unnecessary STRLEN() in make_percent_swname()
Solution: Pass the end of "dir" to make_percent_swname()
          (zeertzjq)

closes: #15340

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 3d6e3a8..f434a13 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    615,
+/**/
     614,
 /**/
     613,