[Bug-openmcl] printing nil with print-pretty set to t

[Larry Pells]

On Yellow Dog Linux 3.0.1 with openmcl 0.14.2, when I use the following code, 
nil does not print the package name when print-pretty is set to t.

Larry.

(defpackage :test (:use))
(loop for a in '(t nil)
   do (let ((*package* (find-package :test))
            (*print-pretty*))
        (print a))
      (let ((*package* (find-package :test))
            (*print-pretty* t))
        (print a)))