patch 9.0.0557: valgrind reports possibly leaked memory

Problem:    Valgrind reports possibly leaked memory.
Solution:   Move the problematic test function to the "fails" test file to
            avoid obscuring real memory leaks.
diff --git a/src/version.c b/src/version.c
index 8df30bd..f01afe3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    557,
+/**/
     556,
 /**/
     555,