Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/amcc/katmai/cmd_katmai.c b/board/amcc/katmai/cmd_katmai.c
index ba71bd5..d362655 100644
--- a/board/amcc/katmai/cmd_katmai.c
+++ b/board/amcc/katmai/cmd_katmai.c
@@ -43,7 +43,7 @@
 	char pcixClock[4];
 
 	if (argc < 3) {
-		printf ("Usage:\n%s\n", cmdtp->usage);
+		cmd_usage(cmdtp);
 		return 1;
 	}