On Linux atomic_dec_and_lock_irqsave is a wrapper macro which provides
a reference to third parameter rather than parameter value itself to
implementation routine called _atomic_dec_and_lock_irqsave [1].

While here, add fast path to implementation [2].

[1] https://github.com/torvalds/linux/blob/master/include/linux/spinlock.h#L476
[2] https://github.com/torvalds/linux/blob/master/lib/dec_and_lock.c#L41