git: openjdk/mobile: 8242485: Null _file checking in fileStream::flush()

[duke]

Changeset: 919027a9
Author:    Denghui Dong <ddong at openjd.org>
Date:      2020-04-14 16:37:36 +0000
URL:       https://git.openjdk.java.net/mobile/commit/919027a9

8242485: Null _file checking in fileStream::flush()

Reviewed-by: dholmes, ysuenaga, iklam

! src/hotspot/share/utilities/ostream.cpp
! src/hotspot/share/utilities/ostream.hpp