missing bus_dmamap_unload() in mpt_timeout()?

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

Further digging through mpt(4)'s timeout handling, I'm getting the impression 
that there's a missing bus_dmamap_unload() for the data buffer 
(for xs->datalen != 0).

However, I neither know whether that's doing any harm nor what happens in case 
the IOC is still using the buffer.