gst: Remove dead assignments and resulting unused variables
gst: Remove dead assignments and resulting unused variables

Merged from gst-plugins-base, 8cd1b5209b68944e1be56ca8bb69e46d4abb7a34.

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