fix top-level comments

R=rsc
DELTA=14  (13 added, 0 deleted, 1 changed)
OCL=17858
CL=17867
diff --git a/src/lib/fmt/print.go b/src/lib/fmt/print.go
index db42c1e..39500f4 100644
--- a/src/lib/fmt/print.go
+++ b/src/lib/fmt/print.go
@@ -4,6 +4,11 @@
 
 package fmt
 
+/*
+	C-like printf, but because of reflection knowledge does not need
+	to be told about sizes and signedness (no %llud etc. - just %d).
+*/
+
 import (
 	"fmt";
 	"reflect";