drm/amd/display: Fix unused initialization of pointer sink

Pointer sink is being inintialized with a value that is never read,
it is later being re-assigned a new value. Remove the redundant
initialization.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -10917,7 +10917,7 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
 	struct amdgpu_dm_connector *amdgpu_dm_connector =
 			to_amdgpu_dm_connector(connector);
 	struct dm_connector_state *dm_con_state = NULL;
-	struct dc_sink *sink = amdgpu_dm_connector->dc_sink;
+	struct dc_sink *sink;
 
 	struct drm_device *dev = connector->dev;
 	struct amdgpu_device *adev = drm_to_adev(dev);