cpu: Do not return errors from cpu_dev_init() which will be ignored

cpu_dev_init() is only called from driver_init(), which does not check
its return value.  Therefore make cpu_dev_init() return void.

We must register the CPU subsystem, so panic if this fails.

If sched_create_sysfs_power_savings_entries() fails, the damage is
contained, so ignore this (as before).

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 7a6ae42..b858dfd 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -94,7 +94,7 @@
 static inline int hypervisor_init(void) { return 0; }
 #endif
 extern int platform_bus_init(void);
-extern int cpu_dev_init(void);
+extern void cpu_dev_init(void);
 
 extern int bus_add_device(struct device *dev);
 extern void bus_probe_device(struct device *dev);