Fix cpu list("-cpu ?") breakage, spotted by TeLeMan

Fix breakage by 04c9a0cbc2.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

cpus.c

@@ -801,3 +801,14 @@ int64_t cpu_get_icount(void)
     }
     return qemu_icount_bias + (icount << icount_time_shift);
 }
+
+void list_cpus(FILE *f, int (*cpu_fprintf)(FILE *f, const char *fmt, ...),
+               const char *optarg)
+{
+    /* XXX: implement xxx_cpu_list for targets that still miss it */
+#if defined(cpu_list_id)
+    cpu_list_id(f, cpu_fprintf, optarg);
+#elif defined(cpu_list)
+    cpu_list(f, cpu_fprintf); /* deprecated */
+#endif
+}

cpus.h

@@ -16,5 +16,7 @@ void vm_state_notify(int running, int reason);
 bool tcg_cpu_exec(void);
 void set_numa_modes(void);
 void set_cpu_log(const char *optarg);
+void list_cpus(FILE *f, int (*cpu_fprintf)(FILE *f, const char *fmt, ...),
+               const char *optarg);
 
 #endif

vl.c

@@ -2726,12 +2726,7 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_cpu:
                 /* hw initialization will check this */
                 if (*optarg == '?') {
-/* XXX: implement xxx_cpu_list for targets that still miss it */
-#if defined(cpu_list_id)
-                    cpu_list_id(stdout, &fprintf, optarg);
-#elif defined(cpu_list)
-                    cpu_list(stdout, &fprintf);	        /* deprecated */
-#endif
+                    list_cpus(stdout, &fprintf, optarg);
                     exit(0);
                 } else {
                     cpu_model = optarg;