Fix omode which inserts an output if none exists (otherwise abc9 breaks)
Fix omode which inserts an output if none exists (otherwise abc9 breaks)

cliffordwolf/yosys,antmicro/yosys,YosysHQ/yosys,cliffordwolf/yosys,antmicro/yosys,SymbiFlow/yosys,cliffordwolf/yosys,YosysHQ/yosys,cliffordwolf/yosys,antmicro/yosys,cliffordwolf/yosys,SymbiFlow/yosys,cliffordwolf/yosys,antmicro/yosys,cliffordwolf/yosys,YosysHQ/yosys,antmicro/yosys,antmicro/yosys,SymbiFlow/yosys,YosysHQ/yosys,SymbiFlow/yosys,cliffordwolf/yosys,SymbiFlow/yosys,SymbiFlow/yosys,SymbiFlow/yosys,YosysHQ/yosys,cliffordwolf/yosys,antmicro/yosys,antmicro/yosys,YosysHQ/yosys,YosysHQ/yosys,YosysHQ/yosys,SymbiFlow/yosys