QtBase: remove explicit function info from qWarning() etc

This information is already registered by the QMessageLogger ctor.

Where, by dropping the << Q_FUNC_INFO in ostream-style qDebug(), only
a string literal remained, converted to printf-style qDebug() on the
go.

Change-Id: I3f261c98fd7bcfa1fead381a75a82713bb75e6f3
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>