6781 zpool man page needs updated to remove duplicate entry of "cannot be" where it discusses cache devices
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 97,108 ****
               devices can be mirrored. However, raidz vdev types are not
               supported for the intent log. For more information, see the
               Intent Log section.
  
       cache   A device used to cache storage pool data. A cache device cannot
!              be cannot be configured as a mirror or raidz group. For more
!              information, see the Cache Devices section.
  
       Virtual devices cannot be nested, so a mirror or raidz virtual device can
       only contain files or disks. Mirrors of mirrors (or other combinations)
       are not allowed.
  
--- 97,108 ----
               devices can be mirrored. However, raidz vdev types are not
               supported for the intent log. For more information, see the
               Intent Log section.
  
       cache   A device used to cache storage pool data. A cache device cannot
!              be configured as a mirror or raidz group. For more information,
!              see the Cache Devices section.
  
       Virtual devices cannot be nested, so a mirror or raidz virtual device can
       only contain files or disks. Mirrors of mirrors (or other combinations)
       are not allowed.
  
*** 1130,1135 ****
       Evolving
  
  SEE ALSO
       zfs(1M), attributes(5), zpool-features(5)
  
! illumos                        February 15, 2016                       illumos
--- 1130,1135 ----
       Evolving
  
  SEE ALSO
       zfs(1M), attributes(5), zpool-features(5)
  
! illumos                         March 25, 2016                         illumos