repo: factor repo usage strings into shared macros

Factor the "git repo info" and "git repo structure" usage
strings into shared macros so they can be reused in multiple
usage arrays.

This is a preparatory refactoring for subsequent changes to
subcommand-specific help output.

Signed-off-by: Mahi Kassa <mahlet.takassa@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: MahiKassa

builtin/repo.c

@@ -20,11 +20,17 @@
 #include "tree-walk.h"
 #include "utf8.h"
 
+#define REPO_INFO_USAGE \
+	"git repo info [--format=(lines|nul) | -z] [--all | <key>...]", \
+	"git repo info --keys [--format=(lines|nul) | -z]"
+
+#define REPO_STRUCTURE_USAGE \
+	"git repo structure [--format=(table|lines|nul) | -z]"
+
 static const char *const repo_usage[] = {
-	"git repo info [--format=(lines|nul) | -z] [--all | <key>...]",
-	"git repo info --keys [--format=(lines|nul) | -z]",
-	"git repo structure [--format=(table|lines|nul) | -z]",
-	NULL
+	REPO_INFO_USAGE,
+	REPO_STRUCTURE_USAGE,
+	NULL,
 };
 
 typedef int get_value_fn(struct repository *repo, struct strbuf *buf);