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/fs-v1.go

@@ -1356,3 +1356,9 @@ func (fs *FSObjects) IsEncryptionSupported() bool {
 func (fs *FSObjects) IsCompressionSupported() bool {
 	return true
 }
+
+// IsReady - Check if the backend disk is ready to accept traffic.
+func (fs *FSObjects) IsReady(_ context.Context) bool {
+	_, err := os.Stat(fs.fsPath)
+	return err == nil
+}