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/common/cmd_nvedit.c b/common/cmd_nvedit.c
index 13325bc..1198954 100644
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -407,10 +407,8 @@
 
 int do_setenv (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
-	if (argc < 2) {
-		cmd_usage(cmdtp);
-		return 1;
-	}
+	if (argc < 2)
+		return cmd_usage(cmdtp);
 
 	return _do_setenv (flag, argc, argv);
 }
@@ -433,15 +431,13 @@
 	local_args[2] = NULL;
 	local_args[3] = NULL;
 
-	if (argc < 2) {
-		cmd_usage(cmdtp);
-		return 1;
-	}
+	if (argc < 2)
+		return cmd_usage(cmdtp);
+
 	/* Check the syntax */
 	switch (argc) {
 	case 1:
-		cmd_usage(cmdtp);
-		return 1;
+		return cmd_usage(cmdtp);
 
 	case 2:		/* askenv envname */
 		sprintf (message, "Please enter '%s':", argv[1]);
@@ -503,10 +499,8 @@
 	char *init_val;
 	int len;
 
-	if (argc < 2) {
-		cmd_usage(cmdtp);
-		return 1;
-	}
+	if (argc < 2)
+		return cmd_usage(cmdtp);
 
 	/* Set read buffer to initial value or empty sting */
 	init_val = getenv(argv[1]);