ttn: fix dest size for some texture instructions

Some, like lod, don't return 4 components.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/gallium/auxiliary/nir/tgsi_to_nir.c

@@ -1464,7 +1464,9 @@ ttn_tex(struct ttn_compile *c, nir_alu_dest dest, nir_ssa_def **src)
 
    assert(src_number == num_srcs);
 
-   nir_ssa_dest_init(&instr->instr, &instr->dest, 4, 32, NULL);
+   nir_ssa_dest_init(&instr->instr, &instr->dest,
+		     nir_tex_instr_dest_size(instr),
+		     32, NULL);
    nir_builder_instr_insert(b, &instr->instr);
 
    /* Resolve the writemask on the texture op. */