shader/arithmetic: Reduce RRO stub severity

src/video_core/shader/decode/arithmetic.cpp

@@ -144,10 +144,11 @@ u32 ShaderIR::DecodeArithmetic(NodeBlock& bb, u32 pc) {
     case OpCode::Id::RRO_C:
     case OpCode::Id::RRO_R:
     case OpCode::Id::RRO_IMM: {
+        LOG_DEBUG(HW_GPU, "(STUBBED) RRO used");
+
         // Currently RRO is only implemented as a register move.
         op_b = GetOperandAbsNegFloat(op_b, instr.alu.abs_b, instr.alu.negate_b);
         SetRegister(bb, instr.gpr0, op_b);
-        LOG_WARNING(HW_GPU, "RRO instruction is incomplete");
         break;
     }
     default: