tests: collectpads: tweak stub _collect to push all buffers
tests: collectpads: tweak stub _collect to push all buffers

https://bugzilla.gnome.org/show_bug.cgi?id=708416

jpakkane/gstreamer,ensonic/gstreamer,Lachann/gstreamer,jpxiong/gstreamer,surround-io/gstreamer,krichter722/gstreamer,ensonic/gstreamer,mparis/gstreamer,ensonic/gstreamer,krichter722/gstreamer,Lachann/gstreamer,Lachann/gstreamer,cablelabs/gstreamer,cablelabs/gstreamer,jpakkane/gstreamer,lovebug356/gstreamer,lovebug356/gstreamer,shelsonjava/gstreamer,surround-io/gstreamer,cfoch/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,mparis/gstreamer,jpxiong/gstreamer,StreamUtils/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,jpakkane/gstreamer,Lachann/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,cfoch/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,lubosz/gstreamer,centricular/gstreamer,Lachann/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,lovebug356/gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,surround-io/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,jpakkane/gstreamer,centricular/gstreamer,surround-io/gstreamer,centricular/gstreamer,cfoch/gstreamer,mparis/gstreamer,shelsonjava/gstreamer,shelsonjava/gstreamer,mparis/gstreamer,mparis/gstreamer,jpakkane/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,lubosz/gstreamer,centricular/gstreamer,ensonic/gstreamer,cablelabs/gstreamer