LU-4629 obdclass: Fix uninitialized variables

LU-4629 obdclass: Fix uninitialized variables

'sd.page_link' is used uninitialized in this function.
'ss.page_link' is used uninitialized in this function.
'sl.page_link' is used uninitialized in this function.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: I5f571fe2b5dc9007720601292484dbf24a348b83
Reviewed-on: http://review.whamcloud.com/10613
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>