patch 8.0.0828: Coverity: may dereference NULL pointer

Problem:    Coverity: may dereference NULL pointer.
Solution:   Bail out if calloc_state() returns NULL.
diff --git a/src/version.c b/src/version.c
index 732e8a5..e7b9fee 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    828,
+/**/
     827,
 /**/
     826,