Update COPYRIGHT to reference zpios CDDL exceptions.

Author: behlendorf

COPYRIGHT

@@ -10,6 +10,10 @@ and attributed properly.  These exceptions include, but are not limited
 to, the vdev_disk.c and zvol.c implementation which are licensed under
 the CDDL.
 
+The zpios test code is originally derived from the Lustre pios test code
+which is licenced under the GPLv2.  As such the heaviliy modified zpios
+kernel test code also remains licensed under the GPLv2.
+
 The latest stable and development versions of this port can be downloaded
 from the official ZFS on Linux site located at:
 
@@ -21,5 +25,7 @@ between the U.S. Department of Energy (DOE) and Lawrence Livermore
 National Security, LLC (LLNS) for the operation of LLNL.  It has been
 approved for release under LLNL-CODE-403049.
 
-This package is distributed under the terms of the CDDL.  See the file
+Unless otherwise noted, all files in this distribution are released
+under the Common Development and Distribution License (CDDL).
+Exceptions are noted within the associated source files.  See the file
 OPENSOLARIS.LICENSE for more information.