fix: heal bucket metadata right before healing bucket (#11097)

optimization mainly to avoid listing the entire
`.minio.sys/buckets/.minio.sys` directory, this
can get really huge and comes in the way of startup
routines, contents inside `.minio.sys/buckets/.minio.sys`
are rather transient and not necessary to be healed.

cmd/storage-rest-client.go

@@ -640,9 +640,9 @@ func newStorageRESTClient(endpoint Endpoint, healthcheck bool) *storageRESTClien
 		healthClient.ExpectTimeouts = true
 		restClient.HealthCheckFn = func() bool {
 			ctx, cancel := context.WithTimeout(GlobalContext, restClient.HealthCheckTimeout)
+			defer cancel()
 			respBody, err := healthClient.Call(ctx, storageRESTMethodHealth, nil, nil, -1)
 			xhttp.DrainBody(respBody)
-			cancel()
 			return toStorageErr(err) != errDiskNotFound
 		}
 	}