top: improve global CPU percentage (smaller & faster code)

diff --git a/procps/Config.in b/procps/Config.in
index cd46a34..fba9e40 100644
--- a/procps/Config.in
+++ b/procps/Config.in
@@ -109,11 +109,11 @@
 	  Make top display CPU usage for each process.
 
 config FEATURE_TOP_CPU_GLOBAL_PERCENTS
-	bool "Show CPU global usage percentage (adds 1k byte)"
+	bool "Show CPU global usage percentage (adds 0.5k byte)"
 	default y
 	depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
 	help
-	  Makes top display "CPU:  n.n% us  n.n% sy  n.n% ni..." line.
+	  Makes top display "CPU: NN% usr NN% sys..." line.
 
 config UPTIME
 	bool "uptime"