firewire: fw-sbp2: fix parsing of logical unit directories

There is a small off-by-one bug in firewire-sbp2. This causes problems
when a device exports multiple LUN Directories. I found it when trying
to talk to a SONY DVD Jukebox.
Signed-off-by: NRichard Sharpe <realrichardsharpe@gmail.com>
Acked-by: NKristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (op. order, changelog)

drivers/firewire/fw-sbp2.c

@@ -1051,7 +1051,8 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
 			break;
 
 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
-			if (sbp2_scan_logical_unit_dir(tgt, ci.p + value) < 0)
+			/* Adjust for the increment in the iterator */
+			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
 				return -ENOMEM;
 			break;
 		}