Remove compiler warning

PiperOrigin-RevId: 663775256
Change-Id: I30fac23e8557ff82901e0d3be1edcba4f39787fd

mpact/sim/util/other/simple_uart.cc

diff --git a/mpact/sim/util/other/simple_uart.cc b/mpact/sim/util/other/simple_uart.cc
index 96a5df7..ffbe3bb 100644
--- a/mpact/sim/util/other/simple_uart.cc
+++ b/mpact/sim/util/other/simple_uart.cc
@@ -11,7 +11,7 @@
 
 // Constructors.
 SimpleUart::SimpleUart(ArchState *state, std::ostream &output)
-    : state_(state), output_(&output) {}
+    : output_(&output) {}
 
 SimpleUart::SimpleUart(ArchState *state) : SimpleUart(state, std::cerr) {}
 

mpact/sim/util/other/simple_uart.h

diff --git a/mpact/sim/util/other/simple_uart.h b/mpact/sim/util/other/simple_uart.h
index ce409e8..6142440 100644
--- a/mpact/sim/util/other/simple_uart.h
+++ b/mpact/sim/util/other/simple_uart.h
@@ -3,7 +3,6 @@
 
 #include <cstdint>
 #include <ostream>
-#include <string>
 
 #include "mpact/sim/generic/arch_state.h"
 #include "mpact/sim/generic/data_buffer.h"
@@ -57,7 +56,6 @@
   // Helper methods.
   uint32_t Read(uint32_t offset);
   void Write(uint32_t offset, uint32_t value);
-  ArchState *state_;
   // The dlab_ bit of the line control register. The dlab bit changes the
   // register map for offsets 0x0 and 0x4 when set.
   bool dlab_ = false;