build system: tidying up CONFIG_xxx names (suggested by Rob)

diff --git a/Config.in b/Config.in
index 85d576e..d2eab53 100644
--- a/Config.in
+++ b/Config.in
@@ -256,18 +256,18 @@
 # These are auto-selected by other options
 
 config FEATURE_SYSLOG
-	bool "Support for logging to syslog"
+	bool #No description makes it a hidden option
 	default n
-	help
-	  This option is auto-selected when you select any applet which may
-	  send its output to syslog. You do not need to select it manually.
+	#help
+	#  This option is auto-selected when you select any applet which may
+	#  send its output to syslog. You do not need to select it manually.
 
 config FEATURE_HAVE_RPC
-	bool "RPC support"
+	bool #No description makes it a hidden option
 	default n
-	help
-	  This is automatically selected if any of enabled applets need it.
-	  You do not need to select it manually.
+	#help
+	#  This is automatically selected if any of enabled applets need it.
+	#  You do not need to select it manually.
 
 endmenu