IconDatabase: Simplify boolean logic in assertion.
https://bugs.webkit.org/show_bug.cgi?id=114425

Reviewed by Andreas Kling.

Follow-up to r148097; drop the overzealous use of !! to turn a
PassRefPtr into a boolean.

* loader/icon/IconDatabase.cpp:
(WebCore::IconDatabase::updateIconRecord):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148194 268f45cc-cd09-0410-ab3c-d52691b4dbfc