scsi: ufs: Check that space was properly alloced in copy_query_response

struct ufs_dev_cmd is the main container that supports device management
commands. In the case of a read descriptor request, we assume that the
proper space was allocated in dev_cmd to hold the returning descriptor.

This is no longer true, as there are flows that doesn't use dev_cmd for
device management requests, and was wrong in the first place.

Fixes: d44a5f98 (ufs: query descriptor API)
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -1917,7 +1917,8 @@ int ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 	memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr, QUERY_OSF_SIZE);
 
 	/* Get the descriptor */
-	if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
+	if (hba->dev_cmd.query.descriptor &&
+	    lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
 		u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
 				GENERAL_UPIU_REQUEST_SIZE;
 		u16 resp_len;