Refactor some of the global variables and commands used by tester.tcl.

FossilOrigin-Name: c2edf8e17f874d0ca4e94b75575bf6e14eea1f05

test/rtree.test

@@ -28,8 +28,7 @@ foreach testfile [lsort -dictionary [glob -nocomplain $rtreedir/*.test]] {
   catch {db close}
   if {$sqlite_open_file_count>0} {
     puts "$tail did not close all files: $sqlite_open_file_count"
-    incr nErr
-    lappend ::failList $tail
+    fail_test $tail
     set sqlite_open_file_count 0
   }
 }