Unless I'm very much missing something these tests are intended to check

Unless I'm very much missing something these tests are intended to check
if bit zero is set, rather than checking if msk is entirely zero (in which
case the logic would be very confusing.  I haven't actually observed any
runtime issues so this may be a misreading of the code on my part.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>