hg: code-tools/jtreg: Fix typo in Defs.gmk, and update modlibs test

[jonathan.gibbons at oracle.com]

Changeset: 35c68ceff115
Author:    jjg
Date:      2018-02-09 13:28 -0800
URL:       http://hg.openjdk.java.net/code-tools/jtreg/rev/35c68ceff115

Fix typo in Defs.gmk, and update modlibs test

! make/Defs.gmk
! test/modlibs/TEST.ROOT