Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_doc.c b/common/cmd_doc.c
index 02502cc..f139d42 100644
--- a/common/cmd_doc.c
+++ b/common/cmd_doc.c
@@ -96,7 +96,7 @@
     switch (argc) {
     case 0:
     case 1:
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
     case 2:
 	if (strcmp(argv[1],"info") == 0) {
@@ -121,7 +121,7 @@
 		doc_print(&doc_dev_desc[curr_device]);
 		return 0;
 	}
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
     case 3:
 	if (strcmp(argv[1],"device") == 0) {
@@ -146,7 +146,7 @@
 		return 0;
 	}
 
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
     default:
 	/* at least 4 args */
@@ -182,7 +182,7 @@
 
 		return ret;
 	} else {
-		printf ("Usage:\n%s\n", cmdtp->usage);
+		cmd_usage(cmdtp);
 		rcode = 1;
 	}
 
@@ -235,7 +235,7 @@
 		offset = simple_strtoul(argv[3], NULL, 16);
 		break;
 	default:
-		printf ("Usage:\n%s\n", cmdtp->usage);
+		cmd_usage(cmdtp);
 		show_boot_progress (-35);
 		return 1;
 	}