[PATCH] sbp2: fix check of return value of hpsb_allocate_and_register_addrspace()

From: Stefan Richter <stefanr@s5r6.in-berlin.de>

I added a failure check in patch "sbp2: variable status FIFO address (fix
login timeout)" --- alas for a wrong error value.  This is a bug since
Linux 2.6.16.  Leads to NULL pointer dereference if the call failed, and
bogus failure handling if call succeeded.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org>
Cc: Ben Collins <bcollins@debian.org>
Cc: Jody McIntyre <scjody@modernduck.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/ieee1394/sbp2.c

@@ -845,7 +845,7 @@ static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud
 			&sbp2_highlevel, ud->ne->host, &sbp2_ops,
 			sizeof(struct sbp2_status_block), sizeof(quadlet_t),
 			0x010000000000ULL, CSR1212_ALL_SPACE_END);
-	if (!scsi_id->status_fifo_addr) {
+	if (scsi_id->status_fifo_addr == ~0ULL) {
 		SBP2_ERR("failed to allocate status FIFO address range");
 		goto failed_alloc;
 	}