staging: lustre: osc: update kms in brw_interpret() properly

In brw_interpret(), we forgot page offset when calculating
write offset, that leads to wrong kms for sync write.
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5463
Reviewed-on: http://review.whamcloud.com/11374Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Li Dongyang <dongyang.li@anu.edu.au>
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>

drivers/staging/lustre/lustre/osc/osc_request.c

@@ -1796,7 +1796,8 @@ static int brw_interpret(const struct lu_env *env,
 
 		if (lustre_msg_get_opc(req->rq_reqmsg) == OST_WRITE) {
 			struct lov_oinfo *loi = cl2osc(obj)->oo_oinfo;
-			loff_t last_off = last->oap_count + last->oap_obj_off;
+			loff_t last_off = last->oap_count + last->oap_obj_off +
+					  last->oap_page_off;
 
 			/* Change file size if this is an out of quota or
 			 * direct IO write and it extends the file size