[PATCH] powerpc: Quiet VETH version printk

ibmveth_printk() is only used to print the driver version when the module
initializes, which means on all machines as long as it's compiled in.

If it's really only needed for debugging, boot with loglevel=8, or get
it from dmesg instead.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>