x264enc: Don't set an allocation maximum
x264enc: Don't set an allocation maximum

There is no reason x264enc should enforce a maximum allocation size.
The maximum is normally set by buffer pool which cannot grow, but we
don't offer a buffer pool. This would lead to stall when used with
element that don't implement allocation query.

Related to: https://bugzilla.gnome.org/show_bug.cgi?id=738302

StreamUtils/gst-plugins-ugly,shelsonjava/gst-plugins-ugly,shelsonjava/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,GStreamer/gst-plugins-ugly,Kurento/gst-plugins-ugly,GStreamer/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,Kurento/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,shelsonjava/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,GStreamer/gst-plugins-ugly,Kurento/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly