staging: lustre: libcfs: fix memort leak in libcfs crypto layer

During code review Boyko discovered a memory leak. This
patch fixes that leak.

Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4423
Reviewed-on: http://review.whamcloud.com/19716


Reviewed-by: Alexander Boyko <alexander.boyko@seagate.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>