[mutter] kms: Fix drmModeEncoder leak

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit abc58f7b9d591f4b9f62b3536938a9ab57137a76
Author: Sebastian Keller <skeller gnome org>
Date:   Fri Jan 24 18:51:03 2020 +0100

    kms: Fix drmModeEncoder leak
    
    The result of drmModeGetEncoder() needs to be free'd by the caller.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/1020

 src/backends/native/meta-kms-connector.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/src/backends/native/meta-kms-connector.c b/src/backends/native/meta-kms-connector.c
index c018a5e62..ce8d28ae0 100644
--- a/src/backends/native/meta-kms-connector.c
+++ b/src/backends/native/meta-kms-connector.c
@@ -381,8 +381,11 @@ set_encoder_device_idx_bit (uint32_t          *encoder_device_idxs,
       if (drm_encoder->encoder_id == encoder_id)
         {
           *encoder_device_idxs |= (1 << i);
+          drmModeFreeEncoder (drm_encoder);
           break;
         }
+
+      drmModeFreeEncoder (drm_encoder);
     }
 }
 
@@ -421,6 +424,8 @@ state_set_crtc_state (MetaKmsConnectorState *state,
 
       if (drm_connector->encoder_id == drm_encoder->encoder_id)
         state->current_crtc_id = drm_encoder->crtc_id;
+
+      drmModeFreeEncoder (drm_encoder);
     }
 
   state->common_possible_crtcs = common_possible_crtcs;