[PATCH] devmem: Handle class_create() failure

[Anton Blanchard <anton@samba.org>]

I hit this when we had a bug in IDR for a few days. Basically sysfs would
fail to create new inodes since it uses an IDR and therefore class_create would
fail.

While we are unlikely to see this fail we may as well handle it instead of
oopsing.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-2.6/drivers/char/mem.c
===================================================================
--- linux-2.6.orig/drivers/char/mem.c	2010-02-02 22:18:02.000000000 -0600
+++ linux-2.6/drivers/char/mem.c	2010-02-02 22:18:15.000000000 -0600
@@ -901,6 +901,9 @@ static int __init chr_dev_init(void)
 		printk("unable to get major %d for memory devs\n", MEM_MAJOR);
 
 	mem_class = class_create(THIS_MODULE, "mem");
+	if (IS_ERR(mem_class))
+		return PTR_ERR(mem_class);
+
 	mem_class->devnode = mem_devnode;
 	for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
 		if (!devlist[minor].name)