When using the Q command in dired to query-replace-regexp across marked
files in dired, the regexp typed in the first prompt highlights text in
the _dired_ buffer.

To reproduce,

        1. emacs -Q
        2. C-x d ~
        3. Q -

Notice how the dashes in the permission fields are highlighted.  This is
misleading and even confusing.  It would be better to turn off regexp
highlighting for this command.  The attached patch does the job on my
end.  Let binding the variable this way does not turn off
lazy-highlighting during the replacement.