LU-2827 mdt: Also handle resend for layout-lock

This patch is an add-on to the generic fix for resends
handling known as :
Lustre-commit: I9a23c13313d5168d0c232fdc0acbdab330089356
Lustre-change: http://review.whamcloud.com/5978/
This patch adds handling of resend during layout-lock

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: Ideb551779a884d77ded8036c513f62557b2dfcde
Reviewed-on: http://review.whamcloud.com/10378
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Vitaly Fertman <vitaly_fertman@xyratex.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>