RFR (XXS): 8228722: jpackage RPM tests fail on some versions of rpmbuild

[Dmitry Chuyko]

Hello,

Please review a tiny fix of a test bug that appears in some 
environments. While extending jpackage platforms support in JDK-8222778 
I used "-E" rpmbuild shortcut for arch detection. It seems to be missing 
in some versions while full "--eval" flag name is more generic.

bug: https://bugs.openjdk.java.net/browse/JDK-8228722

webrev: http://cr.openjdk.java.net/~dchuyko/8228722/webrev.00/

testing: jpackage jtreg tests on x86_64, aarch64 and other archs, Ubuntu 
16.04.

Webrev is made for 'JDK-8200758-branch' branch of open 'sandbox' repo.

-Dmitry