megaraid: fix null pointer check in megasas_detach_one().

commit 546e559c upstream.

The pd_seq_sync pointer can't be NULL, we have to check its entries
instead.
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -5941,7 +5941,7 @@ static void megasas_detach_one(struct pci_dev *pdev)
 			if (fusion->ld_drv_map[i])
 				free_pages((ulong)fusion->ld_drv_map[i],
 					fusion->drv_map_pages);
-				if (fusion->pd_seq_sync)
+			if (fusion->pd_seq_sync[i])
 				dma_free_coherent(&instance->pdev->dev,
 					pd_seq_map_sz,
 					fusion->pd_seq_sync[i],