[IA64] SGI SN drivers: don't report !sn2 hardware as an error

This stuff is all in the generic ia64 kernel, and the new initcall error
reporting complains about them.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

drivers/char/mmtimer.c

@@ -675,7 +675,7 @@ static int __init mmtimer_init(void)
 	cnodeid_t node, maxn = -1;
 
 	if (!ia64_platform_is("sn2"))
-		return -1;
+		return 0;
 
 	/*
 	 * Sanity check the cycles/sec variable

drivers/serial/sn_console.c

@@ -820,7 +820,7 @@ static int __init sn_sal_module_init(void)
 	int retval;
 
 	if (!ia64_platform_is("sn2"))
-		return -ENODEV;
+		return 0;
 
 	printk(KERN_INFO "sn_console: Console driver init\n");