Pull nios2 updates from Ley Foon Tan:

 - nios2: Remove unnecessary #ifdef guards
 - nios2: Switch to generic __xchg()
 - nios2: Fix unused variable warning

* tag 'nios2-v4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  nios2: Remove unnecessary #ifdef guards
  nios2: Switch to generic __xchg()
  nios2: Fix unused variable warning