- Fix races on setting AAC_AIFFLAGS_ALLOCFIBS
- Remove some unused AAC_IFFLAGS_* bits.
Please note that the kthread still makes a difference between the
total mask and AAC_AIFFLAGS_ALLOCFIBS because more flags may be
added in the future to aifflags.
Sponsored by: Sandvine Incorporated
Reported and reviewed by: emaste
MFC after: 2 weeks