Pull btrfs fixes from Chris Mason:
 "Filipe is fixing compile and boot problems with our crc32c rework, and
  Josef has disabled snapshot aware defrag for now.

  As the number of snapshots increases, we're hitting OOM.  For the
  short term we're disabling things until a bigger fix is ready"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: use late_initcall instead of module_init
  Btrfs: use btrfs_crc32c everywhere instead of libcrc32c
  Btrfs: disable snapshot aware defrag for now