pan/midgard: Remove check for class

Fixes classes defaulting to vec4 in some cases.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

src/panfrost/midgard/midgard_ra.c

@@ -492,7 +492,6 @@ allocate_registers(compiler_context *ctx, bool *spilled)
 
         for (unsigned i = 0; i < ctx->temp_count; ++i) {
                 unsigned class = found_class[i];
-                if (!class) continue;
                 ra_set_node_class(g, i, classes[class]);
         }