panfrost: Fix two uninitialized accesses in compiler

panfrost: Fix two uninitialized accesses in compiler

Valgrind was complaining of those.

NIR_PASS only sets progress to TRUE if there was progress.

nir_const_load_to_arr() only sets as many constants as components has
the instruction.

This was causing some dEQP tests to flip-flop, such as:

dEQP-GLES2.functional.fragment_ops.blend.equation_src_func_dst_func.add_src_color_constant_color

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Fixes: 14531d676b11 ("nir: make nir_const_value scalar")