Pull metag architecture fix from James Hogan:
"A simple build fix for irqsoff atomics which has started hitting
meta1_defconfig during the 4.9 merge window"
* tag 'metag-for-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
metag: Only define atomic_dec_if_positive conditionally