Revert "Remove file restrictions when generating clock report data"

This reverts commit 7a73e155a3279a350fbf3ef7ad16cc458233458b.

lisp/org-clock.el

@@ -2091,7 +2091,6 @@ the currently selected interval size."
 	      (with-current-buffer (find-buffer-visiting file)
 		(save-excursion
 		  (save-restriction
-		    (widen)
 		    (push (org-clock-get-table-data file params) tbls))))))
 	;; Just from the current file
 	(save-restriction