backends: Plug leaks

The DRM properties container must be destroyed with
drmModeFreeObjectProperties, and the connectors must be freed on every
caller. Also make it sure that gbm_device structs are destroyed with the
MetaRendererNativeGpuData that owns them.

https://bugzilla.gnome.org/show_bug.cgi?id=789984

src/backends/native/meta-crtc-kms.c

@@ -304,6 +304,8 @@ find_crtc_properties (MetaCrtc   *crtc,
 
       drmModeFreeProperty (prop);
     }
+
+  drmModeFreeObjectProperties (props);
 }
 
 static void

src/backends/native/meta-gpu-kms.c

@@ -141,6 +141,7 @@ meta_gpu_kms_apply_crtc_mode (MetaGpuKms *gpu_kms,
                       mode) != 0)
     {
       g_warning ("Failed to set CRTC mode %s: %m", crtc->current_mode->name);
+      g_free (connectors);
       return FALSE;
     }
 
@@ -224,6 +225,7 @@ meta_gpu_kms_flip_crtc (MetaGpuKms *gpu_kms,
 
   get_crtc_drm_connectors (gpu, crtc, &connectors, &n_connectors);
   g_assert (n_connectors > 0);
+  g_free (connectors);
 
   if (!gpu_kms->page_flips_not_supported)
     {

src/backends/native/meta-renderer-native.c

@@ -243,6 +243,7 @@ meta_renderer_native_gpu_data_free (MetaRendererNativeGpuData *renderer_gpu_data
   if (renderer_gpu_data->egl_display != EGL_NO_DISPLAY)
     meta_egl_terminate (egl, renderer_gpu_data->egl_display, NULL);
 
+  g_clear_pointer (&renderer_gpu_data->gbm.device, gbm_device_destroy);
   g_free (renderer_gpu_data);
 }