RFR 8221096: Description of -XX:+PrintFlagsRanges is incorrect

[Harold Seigel]

Hi,

Please review this trivial change to fix JDK-8221096.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8221096/webrev/index.html

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8221096

The fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-x64, Solaris, Windows, and Mac OS X and by running tier 
3 tests on Linux-x64.

Thanks, Harold