Replace recenly appeared printk with pr_ macro
(the file already use a lot of them).

[ Impact: cleanup ]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090501195425.GB4633@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>