Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/amcc/kilauea/cmd_pll.c b/board/amcc/kilauea/cmd_pll.c
index 0f571fe..3b49e5b 100644
--- a/board/amcc/kilauea/cmd_pll.c
+++ b/board/amcc/kilauea/cmd_pll.c
@@ -183,7 +183,7 @@
 	char c = '\0';
 	pll_freq_t pll_freq;
 	if (argc < 2) {
-		printf("Usage: \n%s\n", cmdtp->usage);
+		cmd_usage(cmdtp);
 		goto ret;
 	}
 
@@ -222,8 +222,8 @@
 		goto ret;
 
 	default:
-		printf("Invalid options"
-		       "\n\nUsage: \n%s\n", cmdtp->usage);
+		printf("Invalid options\n\n");
+		cmd_usage(cmdtp);
 		goto ret;
 	}