x86/microcode: Clean up mc_cpu_down_prep()

x86/microcode: Clean up mc_cpu_down_prep()

commit ba48aa32388ac652256baa8d0a6092d350160da0 upstream

This function has nothing to do with suspend. It's a hotplug
callback. Remove the bogus comment.

Drop the pointless debug printk. The hotplug core provides tracepoints
which track the invocation of those callbacks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231002115903.028651784@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>