[SCSI] qla2xxx: Use 'proper' DID_* status code for dropped-frame scenarios.

The SCSI-midlayer's fast-fail codes consider an DID_ERROR status
as a driver-error and the failed I/O would then be retried in the
midlayer without being fast-failed to dm-multipath.  DID_BUS_BUSY
status returns would induce unneeded path-failures events being
propagated to the DM/MD.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>