RFR(XS): 8209433: [s390] Fix build, broken by 8208672 (Enable -Wreorder)

[Schmidt, Lutz]

Dear all,

I’d like to request reviews for this tiny, s390x only change. The fix is quite similar to JDK-8209357 (ppc). The issue was not immediately detected because -Werror was not active in our build for some reason. Here we go:

Bug:    https://bugs.openjdk.java.net/browse/JDK-8209433
Webrev: http://cr.openjdk.java.net/~lucy/webrevs/8209433.00/

Thank you!
Lutz