Fix initialization order warnings.

Bug 15387371

Change-Id: I01da3db7d6bb795c46153dbc12fd41478f4b6416
Reviewed-on: https://swiftshader-review.googlesource.com/4493
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>