nvmet: use strlcpy() instead of strcpy()

Although the code modified by this patch looks fine to me, this patch avoids
that Coverity reports the following complaint (ID 1364971 and ID 1364973):
"You might overrun the 256-character fixed-size string id->subnqn".
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/admin-cmd.c

@@ -353,7 +353,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	if (req->port->inline_data_size)
 		id->sgls |= cpu_to_le32(1 << 20);
 
-	strcpy(id->subnqn, ctrl->subsys->subsysnqn);
+	strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
 
 	/* Max command capsule size is sqe + single page of in-capsule data */
 	id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +

drivers/nvme/target/discovery.c

@@ -174,7 +174,7 @@ static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req)
 	if (req->port->inline_data_size)
 		id->sgls |= cpu_to_le32(1 << 20);
 
-	strcpy(id->subnqn, ctrl->subsys->subsysnqn);
+	strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
 
 	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));