Docs in OS.java tell us we want microseconds.

Linux impl already provides microsecs, so lets
switch Solaris impl also to micro instead of milli.

Backport of 1439337 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/native/branches/1.1.x@1439341 13f79535-47bb-0310-9956-ffa450edef68
Fix unused variable warning.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/native/branches/1.1.x@1439345 13f79535-47bb-0310-9956-ffa450edef68