h264encode: use frame height not the height from VAImage which may be wrong
h264encode: use frame height not the height from VAImage which may be wrong

Signed-off-by: Austin Yuan <f447c34e4ebcef84a81b40a8d4dbc448a14e5570@intel.com>

01org/libva-cros,chenxianqin/vaapi-libva,01org/libva-cros,01org/iotg-lin-gfx-libva,chenxianqin/vaapi-libva,zzhhui/libva,gbeauchesne/libva,pma1/libva,gbeauchesne/libva,gbeauchesne/libva,pma1/libva,chenxianqin/vaapi-libva,01org/iotg-lin-gfx-libva,01org/iotg-lin-gfx-libva,zzhhui/libva,zzhhui/libva,01org/libva-cros,pma1/libva