hg: code-tools/jtreg: small update to docs

[jonathan.gibbons at oracle.com]

Changeset: 0965c43470bd
Author:    jjg
Date:      2017-12-06 11:42 -0800
URL:       http://hg.openjdk.java.net/code-tools/jtreg/rev/0965c43470bd

small update to docs

! src/share/doc/javatest/regtest/README