Merge branch 'amdkfd-next-3.19' of git://people.freedesktop.org/~gabbayo/linux into drm-next

Just three more fixes for 3.19.
This is the last request until -rc1. I will have our QA team run a full
HSA stack test on 3.19-rc1 and if we find problems, I will send a fixes pull
request.

* 'amdkfd-next-3.19' of git://people.freedesktop.org/~gabbayo/linux:
  amdkfd: Set *buffer_ptr to NULL in case of error
  amdkfd: use atomic allocations within srcu callbacks
  amdkfd: use sizeof(long) granularity for the pasid bitmask