Fix typos in comments (#3415)

plugins/outputs/graphite/graphite.go

@@ -16,7 +16,7 @@ import (
 )
 
 type Graphite struct {
-	// URL is only for backwards compatability
+	// URL is only for backwards compatibility
 	Servers  []string
 	Prefix   string
 	Template string

plugins/outputs/influxdb/influxdb.go

@@ -22,7 +22,7 @@ var (
 
 // InfluxDB struct is the primary data structure for the plugin
 type InfluxDB struct {
-	// URL is only for backwards compatability
+	// URL is only for backwards compatibility
 	URL              string
 	URLs             []string `toml:"urls"`
 	Username         string
@@ -100,7 +100,7 @@ func (i *InfluxDB) Connect() error {
 	var urls []string
 	urls = append(urls, i.URLs...)
 
-	// Backward-compatability with single Influx URL config files
+	// Backward-compatibility with single Influx URL config files
 	// This could eventually be removed in favor of specifying the urls as a list
 	if i.URL != "" {
 		urls = append(urls, i.URL)

plugins/outputs/opentsdb/opentsdb_test.go

@@ -183,7 +183,7 @@ func BenchmarkHttpSend(b *testing.B) {
 // 	err = o.Write(testutil.MockMetrics())
 // 	require.NoError(t, err)
 
-// 	// Verify postive and negative test cases of writing data
+// 	// Verify positive and negative test cases of writing data
 // 	metrics := testutil.MockMetrics()
 // 	metrics = append(metrics, testutil.TestMetric(float64(1.0),
 // 		"justametric.float"))

plugins/outputs/riemann_legacy/riemann.go

@@ -84,7 +84,7 @@ func (r *Riemann) Write(metrics []telegraf.Metric) error {
 
 	var senderr = r.client.SendMulti(events)
 	if senderr != nil {
-		r.Close() // always retuns nil
+		r.Close() // always returns nil
 		return fmt.Errorf("FAILED to send riemann message (will try to reconnect). Error: %s\n",
 			senderr)
 	}