scsi: core: Rename scsi_mq_done() into scsi_done() and export it

Since the removal of the legacy block layer there is only one completion
function left in the SCSI core, namely scsi_mq_done(). Rename it into
scsi_done(). Export that function to allow SCSI LLDs to call it directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-3-bvanassche@acm.org
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_lib.c

@@ -1575,7 +1575,7 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
 	return scsi_cmd_to_driver(cmd)->init_command(cmd);
 }
 
-static void scsi_mq_done(struct scsi_cmnd *cmd)
+void scsi_done(struct scsi_cmnd *cmd)
 {
 	switch (cmd->submitter) {
 	case SUBMITTED_BY_BLOCK_LAYER:
@@ -1593,6 +1593,7 @@ static void scsi_mq_done(struct scsi_cmnd *cmd)
 	trace_scsi_dispatch_cmd_done(cmd);
 	blk_mq_complete_request(scsi_cmd_to_rq(cmd));
 }
+EXPORT_SYMBOL(scsi_done);
 
 static void scsi_mq_put_budget(struct request_queue *q, int budget_token)
 {
@@ -1693,7 +1694,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 	scsi_set_resid(cmd, 0);
 	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
 	cmd->submitter = SUBMITTED_BY_BLOCK_LAYER;
-	cmd->scsi_done = scsi_mq_done;
+	cmd->scsi_done = scsi_done;
 
 	blk_mq_start_request(req);
 	reason = scsi_dispatch_cmd(cmd);

include/scsi/scsi_cmnd.h

@@ -171,6 +171,8 @@ static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 	return *(struct scsi_driver **)rq->rq_disk->private_data;
 }
 
+void scsi_done(struct scsi_cmnd *cmd);
+
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 
 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,