message: don't use typechecking cast macros
message: don't use typechecking cast macros

Simply use casting macros for accessing the message fields like we do for
buffers and events. Avoids some costly typechecking that does not really buy us
much.

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