controller: use g_slice for controlled property structures
controller: use g_slice for controlled property structures

Use g_slide instead of nomal g_new, Also don't init struct with 0 as we need to
init it anyway with the real values.
Also join the 3 flags checks into one.

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