Correct query-param name used by prom-exporter probe (#729)

A previous change introduced the use of the `names` parameter to avoid
exporting metrics, but the correct param-name is `name` (no '-s' suffix).

controllers/util/prometheus_exporter_util.go

@@ -208,7 +208,7 @@ func GenerateSolrPrometheusExporterDeployment(solrPrometheusExporter *solr.SolrP
 		HTTPGet: &corev1.HTTPGetAction{
 			Scheme: corev1.URISchemeHTTP,
 			// TODO: When 9.0 is the minimum supported version, this can be "/-/healthy"
-			Path: "/metrics?names[]=",
+			Path: "/metrics?name[]=",
 			Port: intstr.FromInt(SolrMetricsPort),
 		},
 	}