test/encode: Add -Wall option to default build flags
test/encode: Add -Wall option to default build flags

Signed-off-by: Xiang, Haihao <8d677183e5993577d4fa73a419b76987913292d6@intel.com>

CyanogenMod/android_hardware_intel_libva,CyanogenMod/android_hardware_intel_libva,CyanogenMod/android_hardware_intel_libva,android-ia/hardware_intel_libva,android-ia/hardware_intel_libva,halleyzhao/libva-fdo,android-ia/hardware_intel_libva,halleyzhao/libva-fdo,halleyzhao/libva-fdo