structure: micro-optimisation for some setter functions
structure: micro-optimisation for some setter functions

Split out functions that do the actual work, so we avoid doing
the same g_return_if_fail() checks multiple times for each call.

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