cputlb: Restrict SavedIOTLB to system emulation

Commit 2f3a57e ("cputlb: ensure we save the IOTLB data in
case of reset") added the SavedIOTLB structure -- which is
system emulation specific -- in the generic CPUState structure.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221216215519.5522-3-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/hw/core/cpu.h

@@ -226,7 +226,7 @@ struct CPUWatchpoint {
     QTAILQ_ENTRY(CPUWatchpoint) entry;
 };
 
-#ifdef CONFIG_PLUGIN
+#if defined(CONFIG_PLUGIN) && !defined(CONFIG_USER_ONLY)
 /*
  * For plugins we sometime need to save the resolved iotlb data before
  * the memory regions get moved around  by io_writex.
@@ -410,9 +410,11 @@ struct CPUState {
 
 #ifdef CONFIG_PLUGIN
     GArray *plugin_mem_cbs;
+#if !defined(CONFIG_USER_ONLY)
     /* saved iotlb data from io_writex */
     SavedIOTLB saved_iotlb;
-#endif
+#endif /* !CONFIG_USER_ONLY */
+#endif /* CONFIG_PLUGIN */
 
     /* TODO Move common fields from CPUArchState here. */
     int cpu_index;