vp9_cx_iface,encoder_encode: fix -Wclobbered for pts
vp9_cx_iface,encoder_encode: fix -Wclobbered for pts

Change-Id: Ia7fd4fedb0dcbb626d0e7f4951360e2462b518e2
(cherry picked from commit ae3c6e9ec7dbaad8ee507b1c531c54bdc0141e9f)

webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx