patch 8.0.1622: possible NULL pointer dereference

Problem:    Possible NULL pointer dereferencey. (Coverity)
Solution:   Reverse the check for a NULL pointer.
diff --git a/src/version.c b/src/version.c
index 339ac90..418ca0c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -767,6 +767,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1622,
+/**/
     1621,
 /**/
     1620,