drm/amd/display: Fix memory corruption issue.

temp_flip_context is always same as current_context,
and the current_context will be freed in
dc_commit_targets(), but  temp_flip_context will be used in
dc_update_surfaces_for_target().
Signed-off-by: JimQu <Jim.Qu@amd.com>
Reviewed-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -1096,8 +1096,12 @@ bool dc_commit_targets(
 
 	resource_validate_ctx_destruct(core_dc->current_context);
 
-	dm_free(core_dc->current_context);
+	if (core_dc->temp_flip_context != core_dc->current_context) {
+		dm_free(core_dc->temp_flip_context);
+		core_dc->temp_flip_context = core_dc->current_context;
+	}
 	core_dc->current_context = context;
+	memset(core_dc->temp_flip_context, 0, sizeof(*core_dc->temp_flip_context));
 
 	return (result == DC_OK);