init: Use constant time retries (#8769)

Exponential backoff does not seem like a good fit for
this function since we can expect a few roundtrips on
initial startup.

This retry loop get slow pretty quickly with initial
wait being 1 second and each try being double the
wait until 30 seconds is reached.

Instead simply try 2 times per second.

cmd/prepare-storage.go

@@ -307,13 +307,6 @@ func waitForFormatXL(firstDisk bool, endpoints Endpoints, setCount, drivesPerSet
 		return nil, err
 	}
 
-	// Done channel is used to close any lingering retry routine, as soon
-	// as this function returns.
-	doneCh := make(chan struct{})
-
-	// Indicate to our retry routine to exit cleanly, upon this function return.
-	defer close(doneCh)
-
 	// prepare getElapsedTime() to calculate elapsed time since we started trying formatting disks.
 	// All times are rounded to avoid showing milli, micro and nano seconds
 	formatStartTime := time.Now().Round(time.Second)
@@ -321,13 +314,16 @@ func waitForFormatXL(firstDisk bool, endpoints Endpoints, setCount, drivesPerSet
 		return time.Now().Round(time.Second).Sub(formatStartTime).String()
 	}
 
-	// Wait on the jitter retry loop.
-	retryTimerCh := newRetryTimerSimple(doneCh)
+	// Wait on each try for an update.
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
+	var tries int
 	for {
 		select {
-		case retryCount := <-retryTimerCh:
-			format, err := connectLoadInitFormats(retryCount, firstDisk, endpoints, setCount, drivesPerSet, deploymentID)
+		case <-ticker.C:
+			format, err := connectLoadInitFormats(tries, firstDisk, endpoints, setCount, drivesPerSet, deploymentID)
 			if err != nil {
+				tries++
 				switch err {
 				case errNotFirstDisk:
 					// Fresh setup, wait for first server to be up.