Fixes the following clang warning:
mesa/src/amd/compiler/aco_optimizer.cpp:2928:15: warning: moving a temporary object prevents copy elision [-Wpessimizing-move]
   ctx.uses = std::move(dead_code_analysis(program));
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5228>
          label_instruction(ctx, block, instr);
    }
 
-   ctx.uses = std::move(dead_code_analysis(program));
+   ctx.uses = dead_code_analysis(program);
 
    /* 2. Combine v_mad, omod, clamp and propagate sgpr on VALU instructions */
    for (Block& block : program->blocks) {