LU-4629 gss: fix incorrect memset size

LU-4629 gss: fix incorrect memset size

Function 'memset' is called for 'sizeof' applied to pointer
instead of 'sizeof' applied to pointed type.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: Icd1583cb2de90617f6d96baa5d39d28c0d5167ae
Reviewed-on: http://review.whamcloud.com/9345
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Jenkins
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>