[mutter/gnome-3-36] gpu-kms: Fix compilation issues from backport

[Jonas Ådahl <jadahl src gnome org>]

commit 1f896c9735df41ecd0183a0788530e73320d9e29
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Jun 23 16:25:51 2020 +0200

    gpu-kms: Fix compilation issues from backport
    
    The backport applied cleanly, but didn't build as function type
    signatures called changed. This fixes the compilation issues.

 src/backends/native/meta-gpu-kms.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/backends/native/meta-gpu-kms.c b/src/backends/native/meta-gpu-kms.c
index 061fb01fc7..a475933add 100644
--- a/src/backends/native/meta-gpu-kms.c
+++ b/src/backends/native/meta-gpu-kms.c
@@ -247,10 +247,10 @@ meta_gpu_kms_set_power_save_mode (MetaGpuKms    *gpu_kms,
       /* Turn off CRTCs for DPMS */
       for (l = meta_gpu_get_crtcs (gpu); l; l = l->next)
         {
-          MetaCrtcKms *crtc_kms = META_CRTC_KMS (l->data);
+          MetaCrtc *crtc = META_CRTC (l->data);
 
           meta_kms_update_mode_set (kms_update,
-                                    meta_crtc_kms_get_kms_crtc (crtc_kms),
+                                    meta_crtc_kms_get_kms_crtc (crtc),
                                     NULL, NULL);
         }
     }