diff --color-moved: fix a memory leak

Free the hashmap items as well as the hashmap itself. This was found
with asan.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -5852,8 +5852,8 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 			if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
 				dim_moved_lines(o);
 
-			hashmap_free(&add_lines, 0);
-			hashmap_free(&del_lines, 0);
+			hashmap_free(&add_lines, 1);
+			hashmap_free(&del_lines, 1);
 		}
 
 		for (i = 0; i < esm.nr; i++)