patch 8.2.0888: readdirex() returns size -2 for a directory

Problem:    Readdirex() returns size -2 for a directory.
Solution:   Add missing "else". (Ken Takata, closes #6185)
diff --git a/src/version.c b/src/version.c
index 91d4a46..9522510 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    888,
+/**/
     887,
 /**/
     886,