Actually close connection everytime through the loop.

Also, only use the client when err != nil (c could be non-nil when err == nil)

zfs_replication_exporter.go

@@ -260,19 +260,18 @@ func main() {
 				c, err := ssh.Dial("tcp", host, config)
 				if err != nil {
 					glog.Errorf("Error dialing %q: %v", host, err)
-				}
-				if c != nil {
+				} else {
 					stats, err := fetchSnapshotStats(host, c)
 					if err != nil {
 						glog.Errorf("Failed to update metrics: %v", err)
-						c.Close()
-						c = nil
-					}
+					} else {
 						hss.Lock()
 						hss.host2Stats[host] = stats
 						hss.Unlock()
 						updateMetrics(host, stats)
 					}
+					c.Close()
+				}
 				time.Sleep(*refreshInterval)
 			}
 		}(u, h)