patch 8.2.5089: some functions return a different value on failure

Problem:    Some functions return a different value on failure.
Solution:   Initialize the return value earlier. (Yegappan Lakshmanan,
            closes #10568)
diff --git a/src/version.c b/src/version.c
index 02600f7..aa1319c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5089,
+/**/
     5088,
 /**/
     5087,