Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/pn62/cmd_pn62.c b/board/pn62/cmd_pn62.c
index 3f53e4b..bb98fcf 100644
--- a/board/pn62/cmd_pn62.c
+++ b/board/pn62/cmd_pn62.c
@@ -41,7 +41,7 @@
     unsigned int number, function;
 
     if (argc != 3) {
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
     }
     number = simple_strtoul(argv[1], NULL, 10);
@@ -83,7 +83,7 @@
 	addr = simple_strtoul(argv[1], NULL, 16);
 	break;
     default:
-       printf ("Usage:\n%s\n", cmdtp->usage);
+       cmd_usage(cmdtp);
 	return 1;
     }