cmd_usage(): simplify return code handling

Lots of code use this construct:

	cmd_usage(cmdtp);
	return 1;

Change cmd_usage() let it return 1 - then we can replace all these
ocurrances by

	return cmd_usage(cmdtp);

This fixes a few places with incorrect return code handling, too.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/drivers/qe/qe.c b/drivers/qe/qe.c
index 63cc68e..c4ec2f4 100644
--- a/drivers/qe/qe.c
+++ b/drivers/qe/qe.c
@@ -440,10 +440,8 @@
 {
 	ulong addr;
 
-	if (argc < 3) {
-		cmd_usage(cmdtp);
-		return 1;
-	}
+	if (argc < 3)
+		return cmd_usage(cmdtp);
 
 	if (strcmp(argv[1], "fw") == 0) {
 		addr = simple_strtoul(argv[2], NULL, 16);
@@ -471,8 +469,7 @@
 		return qe_upload_firmware((const struct qe_firmware *) addr);
 	}
 
-	cmd_usage(cmdtp);
-	return 1;
+	return cmd_usage(cmdtp);
 }
 
 U_BOOT_CMD(