scsi: clean obsolete return values of eh_timed_out

Those are no longer in use since commit 242f9dcb
("block: unify request timeout handling").
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/scsi/scsi_host.h

@@ -300,11 +300,7 @@ struct scsi_host_template {
 	/*
 	 * This is an optional routine that allows the transport to become
 	 * involved when a scsi io timer fires. The return value tells the
-	 * timer routine how to finish the io timeout handling:
-	 * EH_HANDLED:		I fixed the error, please complete the command
-	 * EH_RESET_TIMER:	I need more time, reset the timer and
-	 *			begin counting again
-	 * EH_DONE:		Begin normal error recovery
+	 * timer routine how to finish the io timeout handling.
 	 *
 	 * Status: OPTIONAL
 	 */