[ARM] Fix fas216-based data-phase lockups

Ensure SCpnt->request_bufflen is initialised correctly when we
request sense information.

drivers/acorn/scsi/fas216.c

@@ -2213,6 +2213,7 @@ fas216_std_done(FAS216_Info *info, Scsi_Cmnd *SCpnt, unsigned int result)
 	SCpnt->SCp.this_residual = sizeof(SCpnt->sense_buffer);
 	SCpnt->SCp.Message = 0;
 	SCpnt->SCp.Status = 0;
+	SCpnt->request_bufflen = sizeof(SCpnt->sense_buffer);
 	SCpnt->sc_data_direction = SCSI_DATA_READ;
 	SCpnt->use_sg = 0;
 	SCpnt->tag = 0;