scsi: target/tcmu: Fix queue_cmd_ring() declaration

This patch does not change any functionality but avoids that sparse
complains about the queue_cmd_ring() function and its callers.

Fixes: 6fd0ce79 ("tcmu: prep queue_cmd_ring to be used by unmap wq")
Reviewed-by: David Disseldorp <ddiss@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_user.c

@@ -958,7 +958,7 @@ static int add_to_cmdr_queue(struct tcmu_cmd *tcmu_cmd)
  *  0 success
  *  1 internally queued to wait for ring memory to free.
  */
-static sense_reason_t queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, int *scsi_err)
+static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
 {
 	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;