[OpenJDK 2D-Dev] RFR(XXS): 8215130: Fix errors in LittleCMS 2.9 reported by GCC 8

[Dmitry Chuyko]

Hello,

Please review a small fix for type cast error reported by modern 
compiler. It is a port from master repo where the changeset sits above 
2.9 code.

bug: https://bugs.openjdk.java.net/browse/JDK-8215130
webrev: http://cr.openjdk.java.net/~dchuyko/8215130/webrev.00/
3rd party master: 
https://github.com/mm2/Little-CMS/commit/8005ab02c3be0680fecc7c86d719b6c2545b5671
testing: pushed in master on Dec 8th, also checked build and made a dev 
submit repo push

-Dmitry