veyron/services/mgmt/device: Publish under devices/<hostname>

This change makes the device manager publish its name under
devices/<hostname> instead of just <hostname>.

Change-Id: Ia7ead6a2bb0eabcb1c950ab8e8803de0ef2443f9
diff --git a/services/mgmt/device/impl/device_installer.go b/services/mgmt/device/impl/device_installer.go
index 6efb309..ee59788 100644
--- a/services/mgmt/device/impl/device_installer.go
+++ b/services/mgmt/device/impl/device_installer.go
@@ -39,6 +39,7 @@
 	"strings"
 
 	"v.io/core/veyron2/context"
+	"v.io/core/veyron2/naming"
 	"v.io/core/veyron2/services/mgmt/application"
 	"v.io/core/veyron2/services/mgmt/device"
 
@@ -142,7 +143,7 @@
 	}
 	var extraArgs []string
 	if name, err := os.Hostname(); err == nil {
-		extraArgs = append(extraArgs, fmt.Sprintf("--name=%q", name))
+		extraArgs = append(extraArgs, fmt.Sprintf("--name=%q", naming.Join("devices", name)))
 	}
 	if !sessionMode {
 		extraArgs = append(extraArgs, fmt.Sprintf("--restart_exit_code=%d", restartExitCode))
diff --git a/tools/mgmt/test.sh b/tools/mgmt/test.sh
index 0628c47..6441eb7 100755
--- a/tools/mgmt/test.sh
+++ b/tools/mgmt/test.sh
@@ -129,7 +129,7 @@
   fi
 
   "${VRUN}" "${DEVICE_SCRIPT}" start
-  local -r DM_NAME=$(hostname)
+  local -r DM_NAME=devices/$(hostname)
   DM_EP=$(wait_for_mountentry "${NAMESPACE_BIN}" 5 "${DM_NAME}")
 
   # Verify that device manager is published under the expected name (hostname).