Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_jffs2.c b/common/cmd_jffs2.c
index 0818ea8..4c63f51 100644
--- a/common/cmd_jffs2.c
+++ b/common/cmd_jffs2.c
@@ -2289,7 +2289,7 @@
 		return delete_partition(argv[2]);
 	}
 
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
 }
 #endif /* #ifdef CONFIG_JFFS2_CMDLINE */