fixed stupid bug in buffer_span()
fixed stupid bug in buffer_span()

Original commit message from CVS:
fixed stupid bug in buffer_span()

collects/gstreamer,shelsonjava/gstreamer,mparis/gstreamer,mrchapp/gstreamer,ahmedammar/platform_external_gst_gstreamer,mrchapp/gstreamer,jpxiong/gstreamer,StreamUtils/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,drothlis/gstreamer,jpakkane/gstreamer,Lachann/gstreamer,ahmedammar/platform_external_gst_gstreamer,krichter722/gstreamer,lubosz/gstreamer,ensonic/gstreamer,collects/gstreamer,Lachann/gstreamer,mparis/gstreamer,Distrotech/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,cablelabs/gstreamer,cablelabs/gstreamer,centricular/gstreamer,Distrotech/gstreamer,magcius/gstreamer,surround-io/gstreamer,collects/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,krichter722/gstreamer,magcius/gstreamer,ylatuya/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,surround-io/gstreamer,lovebug356/gstreamer,cablelabs/gstreamer,ylatuya/gstreamer,Lachann/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,jpxiong/gstreamer,drothlis/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,justinjoy/gstreamer,lovebug356/gstreamer,cfoch/gstreamer,Distrotech/gstreamer,drothlis/gstreamer,ahmedammar/platform_external_gst_gstreamer,ahmedammar/platform_external_gst_gstreamer,ylatuya/gstreamer,mrchapp/gstreamer,mrchapp/gstreamer,justinjoy/gstreamer,magcius/gstreamer,krichter722/gstreamer,ensonic/gstreamer,magcius/gstreamer,lubosz/gstreamer,cfoch/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,mparis/gstreamer,mrchapp/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,krieger-od/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,Distrotech/gstreamer,collects/gstreamer,magcius/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,justinjoy/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,mparis/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,collects/gstreamer,ylatuya/gstreamer,lubosz/gstreamer,ensonic/gstreamer,centricular/gstreamer,ahmedammar/platform_external_gst_gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,drothlis/gstreamer,cfoch/gstreamer,mparis/gstreamer,krieger-od/gstreamer,Lachann/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,drothlis/gstreamer,cablelabs/gstreamer,ylatuya/gstreamer,cablelabs/gstreamer