Correct docs for long(float).

Doc/lib/libfuncs.tex

@@ -489,8 +489,7 @@ the interpreter.
   Otherwise, the argument may be a plain or
   long integer or a floating point number, and a long integer with
   the same value is returned.    Conversion of floating
-  point numbers to integers is defined by the C semantics;
-  see the description of \function{int()}.
+  point numbers to integers truncates (towards zero).
 \end{funcdesc}
 
 \begin{funcdesc}{map}{function, list, ...}