[mutter] monitor-manager/dummy: Fix name of mode debug env var

[Jonas Ådahl <jadahl src gnome org>]

commit 20731887f2cf5ff6f2734e86573fac87ac9223f1
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Apr 9 13:08:21 2019 +0200

    monitor-manager/dummy: Fix name of mode debug env var
    
    It provides ways to configure the modes, not the actual monitors.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/529

 src/backends/meta-monitor-manager-dummy.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/src/backends/meta-monitor-manager-dummy.c b/src/backends/meta-monitor-manager-dummy.c
index c37ed983c..906773916 100644
--- a/src/backends/meta-monitor-manager-dummy.c
+++ b/src/backends/meta-monitor-manager-dummy.c
@@ -145,7 +145,7 @@ append_monitor (MetaMonitorManager *manager,
   const char *mode_specs_str;
   GList *l;
 
-  mode_specs_str = getenv ("MUTTER_DEBUG_DUMMY_MONITORS_SPECS");
+  mode_specs_str = getenv ("MUTTER_DEBUG_DUMMY_MODE_SPECS");
   if (mode_specs_str && *mode_specs_str != '\0')
     {
       g_auto (GStrv) specs = g_strsplit (mode_specs_str, ":", -1);
@@ -397,10 +397,11 @@ meta_monitor_manager_dummy_read_current (MetaMonitorManager *manager)
    * Specifies the number of dummy monitors to include in the stage. Every
    * monitor is 1024x786 pixels and they are placed on a horizontal row.
    *
-   * MUTTER_DEBUG_DUMMY_MONITORS_SPECS
+   * MUTTER_DEBUG_DUMMY_MODE_SPECS
    *
-   * A colon separated list of monitor specifications that can be used to
-   * configure the monitor via dbus API.
+   * A colon separated list of mode specifications that can be used to
+   * configure the monitor via dbus API. Setting this environment variable
+   * overrides the default set of modes available.
    * Format should be WWxHH:WWxHH@RR
    *
    * MUTTER_DEBUG_DUMMY_MONITOR_SCALES