Fix inclusion of binary file changes in Perforce diffs.
Review Request #10326 — Created Nov. 19, 2018 and submitted
The diff code for Perforce clients was mistakenly filtering out changes
to binary files. This change fixes it.
Created a perforce client with a change to a binary file. Before,
posting the changeset would show only the text files. After, it shows
the expected "This is a binary file" line in the diff viewer.
We should explicitly check dl's value, or a false result becomes the value of dl ( in this case).