va_parseConfig: still need to check env_value
va_parseConfig: still need to check env_value

env_value may be NULL which means the caller doens't
care the value of the environment variable, just check
if it is set.

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

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