pulsesink: Free format_info in query_getcaps
pulsesink: Free format_info in query_getcaps

If we can not create probe stream in query_getcaps function, it will appear
memory leakage from format info.
The following patch prevent memory leakage in pulsesink.

https://bugzilla.gnome.org/show_bug.cgi?id=743178

ndufresne/gst-plugins-good,ndufresne/gst-plugins-good,ndufresne/gst-plugins-good,vatavuserban/gst-plugins-good,vatavuserban/gst-plugins-good,vatavuserban/gst-plugins-good,ndufresne/gst-plugins-good,vatavuserban/gst-plugins-good