(Fsetq): Doc fix.

src/eval.c

@@ -414,7 +414,8 @@ whose values are discarded.")
 DEFUN ("setq", Fsetq, Ssetq, 0, UNEVALLED, 0,
   "(setq SYM VAL SYM VAL ...): set each SYM to the value of its VAL.\n\
 The SYMs are not evaluated.  Thus (setq x y) sets x to the value of y.\n\
-Each SYM is set before the next VAL is computed.")
+Each SYM is set before the next VAL is computed.
+The return value of the `setq' form is the value of the last VAL.")
   (args)
      Lisp_Object args;
 {