allowing their use to be disabled via device hints though). This matches
what the corresponding Linux driver provided by LSI does. Tested with
SAS1064.
- There's no need to keep track of the RIDs used.
- Don't allocate MSI/MSI-X as RF_SHAREABLE.
- Remove a comment which no longer applies since r209599.
- Assign NULL rather than 0 to pointers.
MFC after: 1 month