directsoundsink: Clean up some debug logging
directsoundsink: Clean up some debug logging

Don't need to print the function name, gstreamer does it for you.

https://bugzilla.gnome.org/show_bug.cgi?id=773681

GStreamer/gst-plugins-good,pexip/gst-plugins-good,GrokImageCompression/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,GrokImageCompression/gst-plugins-good,hizukiayaka/gst-plugins-good,hizukiayaka/gst-plugins-good,hizukiayaka/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,GrokImageCompression/gst-plugins-good,GrokImageCompression/gst-plugins-good,pexip/gst-plugins-good,StreamUtils/gst-plugins-good,StreamUtils/gst-plugins-good,StreamUtils/gst-plugins-good,pexip/gst-plugins-good,StreamUtils/gst-plugins-good,GStreamer/gst-plugins-good,hizukiayaka/gst-plugins-good