lib: Make instdone initialisation fail gracefully

Just report that we don't recognise the chipset rather than explode.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tools/intel_error_decode.c b/tools/intel_error_decode.c
index c710212..a7a65e8 100644
--- a/tools/intel_error_decode.c
+++ b/tools/intel_error_decode.c
@@ -97,7 +97,8 @@
 	static int once;
 
 	if (!once) {
-		init_instdone_definitions(devid);
+		if (!init_instdone_definitions(devid))
+			return;
 		once = 1;
 	}