hg: jdk/jdk10: 8194742: Writing replay data crashes: task is NULL

[tobias.hartmann at oracle.com]

Changeset: 13f6856e8489
Author:    goetz
Date:      2018-01-09 16:24 +0100
URL:       http://hg.openjdk.java.net/jdk/jdk10/rev/13f6856e8489

8194742: Writing replay data crashes: task is NULL
Summary: Added missing NULL check.
Reviewed-by: thartmann

! src/hotspot/share/ci/ciEnv.cpp