commit-graph: rename 'split_commit_graph_opts'

In the subsequent commit, additional options will be added to the
commit-graph API which have nothing to do with splitting.

Rename the 'split_commit_graph_opts' structure to the more-generic
'commit_graph_opts' to encompass both. Likewise, rename the 'flags'
member to instead be 'split_flags' to clarify that it only has to do
with the behavior implied by '--split'.

Suggested-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index ba55844..f3243bd 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -119,7 +119,7 @@ static int graph_verify(int argc, const char **argv)
 }
 
 extern int read_replace_refs;
-static struct split_commit_graph_opts split_opts;
+static struct commit_graph_opts write_opts;
 
 static int write_option_parse_split(const struct option *opt, const char *arg,
 				    int unset)
@@ -187,24 +187,24 @@ static int graph_write(int argc, const char **argv)
 		OPT_BOOL(0, "changed-paths", &opts.enable_changed_paths,
 			N_("enable computation for changed paths")),
 		OPT_BOOL(0, "progress", &opts.progress, N_("force progress reporting")),
-		OPT_CALLBACK_F(0, "split", &split_opts.flags, NULL,
+		OPT_CALLBACK_F(0, "split", &write_opts.split_flags, NULL,
 			N_("allow writing an incremental commit-graph file"),
 			PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 			write_option_parse_split),
-		OPT_INTEGER(0, "max-commits", &split_opts.max_commits,
+		OPT_INTEGER(0, "max-commits", &write_opts.max_commits,
 			N_("maximum number of commits in a non-base split commit-graph")),
-		OPT_INTEGER(0, "size-multiple", &split_opts.size_multiple,
+		OPT_INTEGER(0, "size-multiple", &write_opts.size_multiple,
 			N_("maximum ratio between two levels of a split commit-graph")),
-		OPT_EXPIRY_DATE(0, "expire-time", &split_opts.expire_time,
+		OPT_EXPIRY_DATE(0, "expire-time", &write_opts.expire_time,
 			N_("only expire files older than a given date-time")),
 		OPT_END(),
 	};
 
 	opts.progress = isatty(2);
 	opts.enable_changed_paths = -1;
-	split_opts.size_multiple = 2;
-	split_opts.max_commits = 0;
-	split_opts.expire_time = 0;
+	write_opts.size_multiple = 2;
+	write_opts.max_commits = 0;
+	write_opts.expire_time = 0;
 
 	trace2_cmd_mode("write");
 
@@ -232,7 +232,7 @@ static int graph_write(int argc, const char **argv)
 	odb = find_odb(the_repository, opts.obj_dir);
 
 	if (opts.reachable) {
-		if (write_commit_graph_reachable(odb, flags, &split_opts))
+		if (write_commit_graph_reachable(odb, flags, &write_opts))
 			return 1;
 		return 0;
 	}
@@ -261,7 +261,7 @@ static int graph_write(int argc, const char **argv)
 			       opts.stdin_packs ? &pack_indexes : NULL,
 			       opts.stdin_commits ? &commits : NULL,
 			       flags,
-			       &split_opts))
+			       &write_opts))
 		result = 1;
 
 cleanup: