Fix Readiness check (#8681)

- Remove goroutine-check in Readiness check
- Bring in quorum check for readiness

Fixes #8385

Co-authored-by: Harshavardhana <harsha@minio.io>

cmd/xl-zones.go

@@ -1359,3 +1359,16 @@ func (z *xlZones) GetMetrics(ctx context.Context) (*Metrics, error) {
 	logger.LogIf(ctx, NotImplemented{})
 	return &Metrics{}, NotImplemented{}
 }
+
+// IsReady - Returns True if all the zones have enough quorum to accept requests.
+func (z *xlZones) IsReady(ctx context.Context) bool {
+	if z.SingleZone() {
+		return z.zones[0].IsReady(ctx)
+	}
+	for _, xlsets := range z.zones {
+		if !xlsets.IsReady(ctx) {
+			return false
+		}
+	}
+	return true
+}