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/arch/powerpc/cpu/mpc8260/bedbug_603e.c b/arch/powerpc/cpu/mpc8260/bedbug_603e.c
index 2488612..89193a3 100644
--- a/arch/powerpc/cpu/mpc8260/bedbug_603e.c
+++ b/arch/powerpc/cpu/mpc8260/bedbug_603e.c
@@ -71,10 +71,7 @@
   /* -------------------------------------------------- */
 
   if (argc < 2)
-  {
-    cmd_usage(cmdtp);
-    return;
-  }
+    return cmd_usage(cmdtp);
 
   /* Turn off a breakpoint */
 
@@ -118,10 +115,7 @@
   if(!(( isdigit( argv[ 1 ][ 0 ] )) ||
 	(( argv[ 1 ][ 0 ] >= 'a' ) && ( argv[ 1 ][ 0 ] <= 'f' )) ||
 	(( argv[ 1 ][ 0 ] >= 'A' ) && ( argv[ 1 ][ 0 ] <= 'F' ))))
-  {
-    cmd_usage(cmdtp);
-    return;
-  }
+    return cmd_usage(cmdtp);
 
   addr = simple_strtoul( argv[ 1 ], NULL, 16 );