scsi: dc395: Fix error case unwinding

dc395x_init_one()->adapter_init() might fail. In this case, the acb is
already cleaned up by adapter_init(), no need to do that in
adapter_uninit(acb) again.

[    1.252251] dc395x: adapter init failed
[    1.254900] RIP: 0010:adapter_uninit+0x94/0x170 [dc395x]
[    1.260307] Call Trace:
[    1.260442]  dc395x_init_one.cold+0x72a/0x9bb [dc395x]

Link: https://lore.kernel.org/r/20210907040702.1846409-1-ztong0001@gmail.com
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/dc395x.c

@@ -4618,6 +4618,7 @@ static int dc395x_init_one(struct pci_dev *dev, const struct pci_device_id *id)
 	/* initialise the adapter and everything we need */
  	if (adapter_init(acb, io_port_base, io_port_len, irq)) {
 		dprintkl(KERN_INFO, "adapter init failed\n");
+		acb = NULL;
 		goto fail;
 	}