scsi: ufs: core: Add NULL check in ufshcd_mcq_compl_pending_transfer()

Add a NULL check for the returned hwq pointer by ufshcd_mcq_req_to_hwq().

This is similar to the fix in commit 7473610 ("scsi: ufs: core: Fix
ufshcd_abort_one racing issue").

Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Link: https://lore.kernel.org/r/20250412195909.315418-1-chenyuan0y@gmail.com
Fixes: ab24864 ("scsi: ufs: core: Add error handling for MCQ mode")
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufshcd.c

@@ -5678,6 +5678,8 @@ static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
 			continue;
 
 		hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
+		if (!hwq)
+			continue;
 
 		if (force_compl) {
 			ufshcd_mcq_compl_all_cqes_lock(hba, hwq);