Make it even with gotctl.8

diff /home/misha/work/got
commit - b18b22548b5f83b9ec2eaf63b161fa5f76febdbc
path + /home/misha/work/got
blob - afc36213377900db760b4124017a746dbcc4cdf4
file + gotctl/gotctl.c
--- gotctl/gotctl.c
+++ gotctl/gotctl.c
@@ -314,7 +314,7 @@ usage(int hflag, int status)
 {
 	FILE *fp = (status == 0) ? stdout : stderr;
 
-	fprintf(fp, "usage: %s [-hV] command [arg ...]\n",
+	fprintf(fp, "usage: %s [-hV] [-f path] command [arg ...]\n",
 	    getprogname());
 	if (hflag)
 		list_commands(fp);