The recent conversion of the console hotplug notifier to the state machine
missed the fact, that the notifier only operated on the non frozen
transitions. As a consequence the console_lock/unlock() pair is also
invoked during suspend, which results in a lockdep warning.

Restore the previous state by making the lock/unlock conditional on
!tasks_frozen.

Fixes: 90b14889 ("kernel/printk: Convert to hotplug state machine")
Reported-and-tested-by: NBorislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611171729320.3645@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>