Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "These fix one mishandling of the case when security labels are
  configured out, and two races in the 4.1 backchannel code"

* 'for-3.18' of git://linux-nfs.org/~bfields/linux:
  nfsd: Fix slot wake up race in the nfsv4.1 callback code
  SUNRPC: Fix locking around callback channel reply receive
  nfsd: correctly define v4.2 support attributes