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: Richard Sharpe <realrichardsharpe@gmail.com>
Acked-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (op. order, changelog)
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index b2458bb..227d2e0 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -1051,7 +1051,8 @@
 			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;
 		}