exec/cpu: Have cpu_exec_realize() return a boolean

Following the example documented since commit e3fe3988d7 ("error:
Document Error API usage rules"), have cpu_exec_realizefn()
return a boolean indicating whether an error is set or not.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230918160257.30127-22-philmd@linaro.org>
diff --git a/cpu-target.c b/cpu-target.c
index 79363ae..f3e1ad8 100644
--- a/cpu-target.c
+++ b/cpu-target.c
@@ -131,13 +131,13 @@
 };
 #endif
 
-void cpu_exec_realizefn(CPUState *cpu, Error **errp)
+bool cpu_exec_realizefn(CPUState *cpu, Error **errp)
 {
     /* cache the cpu class for the hotpath */
     cpu->cc = CPU_GET_CLASS(cpu);
 
     if (!accel_cpu_common_realize(cpu, errp)) {
-        return;
+        return false;
     }
 
     /* Wait until cpu initialization complete before exposing cpu. */
@@ -159,6 +159,8 @@
         vmstate_register(NULL, cpu->cpu_index, cpu->cc->sysemu_ops->legacy_vmsd, cpu);
     }
 #endif /* CONFIG_USER_ONLY */
+
+    return true;
 }
 
 void cpu_exec_unrealizefn(CPUState *cpu)