MFC:
If we get a DATA UNDERRUN error from QLogic FC cards, but the RQCS_RU bit
is not set in the scsi completion status, or if the residual is clearly
nonsense, then this was a command that suffered the loss of one or more
FC frames in the middle of the exchange.
Set HBA_BOTCH and hope it will get retried. It's the only thing we can do.
Approved by: re@freebsd.org