megaraid: fix null pointer check in megasas_detach_one().

BugLink: http://bugs.launchpad.net/bugs/1544679

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>
(cherry picked from linux-next commit bd27c97fae40ff3a96e91750304296d851b3c5f2)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -6294,11 +6294,11 @@ 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)
-					dma_free_coherent(&instance->pdev->dev,
-						pd_seq_map_sz,
-						fusion->pd_seq_sync[i],
-						fusion->pd_seq_phys[i]);
+			if (fusion->pd_seq_sync[i])
+				dma_free_coherent(&instance->pdev->dev,
+					pd_seq_map_sz,
+					fusion->pd_seq_sync[i],
+					fusion->pd_seq_phys[i]);
 		}
 		free_pages((ulong)instance->ctrl_context,
 			instance->ctrl_context_pages);