setup: fix leaking repository format

While populating the `repository_format` structure may cause us to
allocate memory, we do not call `clear_repository_format()` in some
places and thus potentially leak memory. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

setup.c

@@ -722,6 +722,7 @@ int upgrade_repository_format(int target_version)
 	ret = 1;
 
 out:
+	clear_repository_format(&repo_fmt);
 	strbuf_release(&repo_version);
 	strbuf_release(&err);
 	return ret;
@@ -2199,6 +2200,7 @@ int init_db(const char *git_dir, const char *real_git_dir,
 			       git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 	}
 
+	clear_repository_format(&repo_fmt);
 	free(original_git_dir);
 	return 0;
 }