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>
(cherry picked from commit 2e11d2273b2974a7d1959cbcaf8db5b8e9aedd9e)

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