Fix install directory issue PR pkg/54183, thanks wiz@ and leot@ for review

Install destination inconsistency if PKG_REVISION is set.
The part of error message looks as:

ERROR: The following files are in the PLIST but not in /W/devel/rubymine-bin/work/.destdir/usr/pkg:
ERROR:        /W/devel/rubymine-bin/work/.destdir/usr/pkg/${PKGNAME_NOREV}/Install-Linux-tar.txt
      .....
      ....
ERROR: ************************************************************
ERROR: The following files are in /W/devel/rubymine-bin/work/.destdir/usr/pkg but not in the PLIST:
ERROR:        /W/devel/rubymine-bin/work/.destdir/usr/pkg/rubymine-bin-2018.3.5nb1/Install-Linux-tar.txt

(mef)