Update verilog_frontend.cc

`read_verilog_file_list` should not try to read arguments as selection args.  Without this, trying to pass a file without a `-f|-F` flag is misleading, in the best case giving a warning about the selection not matching any module, or in worst case just doing nothing (if the filename is a valid selection).

frontends/verilog/verilog_frontend.cc

@@ -753,7 +753,7 @@ struct VerilogFileList : public Pass {
 			break;
 		}
 
-		extra_args(args, argidx, design);
+		extra_args(args, argidx, design, false);
 	}
 } VerilogFilelist;