Merge branch 'ds/commit-graph-expiry-fix'

"git commit-graph write --expire-time=<timestamp>" did not use the
given timestamp correctly, which has been corrected.

* ds/commit-graph-expiry-fix:
  commit-graph: fix buggy --expire-time option

builtin/commit-graph.c

@@ -143,7 +143,7 @@ static int graph_write(int argc, const char **argv)
 		OPT_INTEGER(0, "size-multiple", &split_opts.size_multiple,
 			N_("maximum ratio between two levels of a split commit-graph")),
 		OPT_EXPIRY_DATE(0, "expire-time", &split_opts.expire_time,
-			N_("maximum number of commits in a non-base split commit-graph")),
+			N_("only expire files older than a given date-time")),
 		OPT_END(),
 	};