tiocx: check retval from bus_register()

Properly check return value from bus_register() and propagate it out of
tiocx_init() in case of failure.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/tiocx.c

@@ -490,11 +490,14 @@ static int __init tiocx_init(void)
 {
 	cnodeid_t cnodeid;
 	int found_tiocx_device = 0;
+	int err;
 
 	if (!ia64_platform_is("sn2"))
 		return 0;
 
-	bus_register(&tiocx_bus_type);
+	err = bus_register(&tiocx_bus_type);
+	if (err)
+		return err;
 
 	for (cnodeid = 0; cnodeid < num_cnodes; cnodeid++) {
 		nasid_t nasid;