Fix MX tool config script to make the tool work with TESTNG.
In the fix JDK-8152344 a small mistake has been made.

A small change needs to be done in hotspot/.mx.jvmci/suite.py

--- a/.mx.jvmci/suite.py Thu Mar 31 09:26:13 2016 +0200
+++ b/.mx.jvmci/suite.py Thu Mar 31 11:42:25 2016 +0300
@@ -164,7 +164,7 @@
       "subDir" : "test/compiler/jvmci",
       "sourceDirs" : ["src"],
       "dependencies" : [
- "mx:TESTNG",
+ "TESTNG",
         "jdk.vm.ci.hotspot",
       ],
       "checkstyle" : "jdk.vm.ci.services",