pixman-renderer: copy_to_hw_buffer: don't leak output_region

This was reported by Valgrind.

Signed-off-by: Ryo Munakata <ryomnktml@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/src/pixman-renderer.c b/src/pixman-renderer.c
index 351f00e..2c26c3a 100644
--- a/src/pixman-renderer.c
+++ b/src/pixman-renderer.c
@@ -457,6 +457,7 @@
 	region_global_to_output(output, &output_region);
 
 	pixman_image_set_clip_region32 (po->hw_buffer, &output_region);
+	pixman_region32_fini(&output_region);
 
 	pixman_image_composite32(PIXMAN_OP_SRC,
 				 po->shadow_image, /* src */