scsi: cxlflash: Update cxlflash_afu_sync() to return errno

The cxlflash_afu_sync() routine returns a negative one to indicate any kind
of failure. This makes it impossible to establish why the error occurred.

Update the return codes to clearly indicate the failure cause to the
caller.
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/main.c

@@ -2022,8 +2022,7 @@ static int init_afu(struct cxlflash_cfg *cfg)
  * going away).
  *
  * Return:
- *	0 on success
- *	-1 on failure
+ *	0 on success, -errno on failure
  */
 int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 		      res_hndl_t res_hndl_u, u8 mode)
@@ -2047,7 +2046,7 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 	buf = kzalloc(sizeof(*cmd) + __alignof__(*cmd) - 1, GFP_KERNEL);
 	if (unlikely(!buf)) {
 		dev_err(dev, "%s: no memory for command\n", __func__);
-		rc = -1;
+		rc = -ENOMEM;
 		goto out;
 	}
 
@@ -2071,12 +2070,14 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 	*((__be32 *)&cmd->rcb.cdb[4]) = cpu_to_be32(res_hndl_u);
 
 	rc = afu->send_cmd(afu, cmd);
-	if (unlikely(rc))
+	if (unlikely(rc)) {
+		rc = -ENOBUFS;
 		goto out;
+	}
 
 	rc = wait_resp(afu, cmd);
 	if (unlikely(rc))
-		rc = -1;
+		rc = -EIO;
 out:
 	atomic_dec(&afu->cmds_active);
 	mutex_unlock(&sync_active);