mesa: fix format conversion bug in get_tex_rgba_uncompressed()

We need to set the need_convert flag with each loop iteration, not
just when the rgba pointer is null.

Bug reported by Markus Müller <mueller@imfusion.de> on mesa-users list.
Fixes new piglit arb_texture_float-get-tex3d test.

Cc: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
1 file changed