nvme: add helper nvme_cleanup_cmd()

This hides command cleanup into nvme.h and fabrics drivers will
also use it.

Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/host/nvme.h

@@ -182,6 +182,12 @@ static inline unsigned nvme_map_len(struct request *rq)
 		return blk_rq_bytes(rq);
 }
 
+static inline void nvme_cleanup_cmd(struct request *req)
+{
+	if (req->cmd_flags & REQ_DISCARD)
+		kfree(req->completion_data);
+}
+
 static inline int nvme_error_status(u16 status)
 {
 	switch (status & 0x7ff) {

drivers/nvme/host/pci.c

@@ -321,8 +321,7 @@ static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
 	__le64 **list = iod_list(req);
 	dma_addr_t prp_dma = iod->first_dma;
 
-	if (req->cmd_flags & REQ_DISCARD)
-		kfree(req->completion_data);
+	nvme_cleanup_cmd(req);
 
 	if (iod->npages == 0)
 		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);