nohz: Remove "Switched to NOHz mode" debugging messages

When performing cpu hotplug tests the kernel printk log buffer gets flooded
with pointless "Switched to NOHz mode..." messages. Especially when afterwards
analyzing a dump this might have removed more interesting stuff out of the
buffer.
Assuming that switching to NOHz mode simply works just remove the printk.

Change-Id: I1746f8c0119a512055716c3fd77a966b735ca49b
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: http://lkml.kernel.org/r/20110823112046.GB2540@osiris.boeblingen.de.ibm.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>