format-{control,arguments} in simple-progress-condition in src/condit…

…ions.lisp

* src/conditions.lisp (simple-progress-condition): added default
  initargs format-control and format-arguments
* test/conditions.lisp (test maybe-print-explanation.print): do not try
  to construct an instance without format-control and format-arguments
  initargs on on-sbcl

src/conditions.lisp

@@ -294,6 +294,9 @@
 (define-condition simple-progress-condition (progress-condition
                                              simple-condition)
   ()
+  #-sbcl (:default-initargs
+          :format-control   nil
+          :format-arguments '())
   (:documentation
    "Like `progress-condition' but supports format control and format
     arguments to produce a report to go along with the raw progress

test/conditions.lisp

@@ -85,7 +85,7 @@
                    (apply #'make-condition 'simple-foo-error initargs)))))
 
    '(;; No format-control.
-     (()
+     #+sbcl (()
       "Foo-error occurred.")
      ;; With format-control.
      ((:format-control   "the number was ~S."