gstpad: Move sticky flag clearing code to gst_pad_activate_mode
gstpad: Move sticky flag clearing code to gst_pad_activate_mode

The ghostpad code directly activates/deactivates the child code by
calling gst_pad_activate_mode, rather than gst_pad_set_active, so
make sure to clear the flags in gst_pad_activate_mode(), which should
catch all cases.

ensonic/gstreamer,lovebug356/gstreamer,shelsonjava/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,mparis/gstreamer,StreamUtils/gstreamer,jpakkane/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,jpxiong/gstreamer,cfoch/gstreamer,Lachann/gstreamer,lubosz/gstreamer,collects/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,collects/gstreamer,cablelabs/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,surround-io/gstreamer,centricular/gstreamer,centricular/gstreamer,collects/gstreamer,justinjoy/gstreamer,centricular/gstreamer,lubosz/gstreamer,justinjoy/gstreamer,cfoch/gstreamer,shelsonjava/gstreamer,surround-io/gstreamer,lovebug356/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,Lachann/gstreamer,krichter722/gstreamer,cfoch/gstreamer,jpxiong/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,lovebug356/gstreamer,collects/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,lubosz/gstreamer,mparis/gstreamer,collects/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,ensonic/gstreamer,ensonic/gstreamer,surround-io/gstreamer,Lachann/gstreamer,cfoch/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,mparis/gstreamer,justinjoy/gstreamer,mparis/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer,ensonic/gstreamer,krichter722/gstreamer,surround-io/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer