cciss: Fix excessive gendisk freeing bug on driver unload.

Fix bug that free_hba was calling put_disk for all gendisk[]
pointers -- all 1024 of them -- regardless of whether the were
used or not (NULL).  This bug could cause rmmod to oops if logical
drives had been deleted during the driver's lifetime.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

drivers/block/cciss.c

@@ -3893,15 +3893,16 @@ static int alloc_cciss_hba(void)
 	return -1;
 }
 
-static void free_hba(int i)
+static void free_hba(int n)
 {
-	ctlr_info_t *p = hba[i];
-	int n;
+	ctlr_info_t *h = hba[n];
+	int i;
 
-	hba[i] = NULL;
-	for (n = 0; n < CISS_MAX_LUN; n++)
-		put_disk(p->gendisk[n]);
-	kfree(p);
+	hba[n] = NULL;
+	for (i = 0; i < h->highest_lun + 1; i++)
+		if (h->gendisk[i] != NULL)
+			put_disk(h->gendisk[i]);
+	kfree(h);
 }
 
 /* Send a message CDB to the firmware. */