[PATCH v2 12/15] linux-user: Uncast void pointer argument as Object in target_cpu_free()

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

init_main_thread() is registered as Object::free() hook, thus
take an Object* argument. Uncast the void pointer as such.

While now cpu_env() accept any pointer type, next commit will
restrict it to CPUState* type. QOM-cast the Object to CPU type,
otherwise we will get:

  ../linux-user/i386/cpu_loop.c: In function ‘target_cpu_free’:
  include/hw/core/cpu.h:604:31: error: ‘_Generic’ selector of type ‘void’ is not compatible with any association
../linux-user/x86_64/../i386/cpu_loop.c:331:19: note: in expansion of macro ‘cpu_env’
  331 |     target_munmap(cpu_env(obj)->gdt.base,
      |                   ^~~~~~~

Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 linux-user/i386/cpu_loop.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index fe922fceb5a..a0790f3f352 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -326,9 +326,10 @@ void cpu_loop(CPUX86State *env)
     }
 }
 
-static void target_cpu_free(void *obj)
+static void target_cpu_free(void *ptr)
 {
-    target_munmap(cpu_env(obj)->gdt.base,
+    Object *obj = ptr;
+    target_munmap(cpu_env(CPU(obj))->gdt.base,
                   sizeof(uint64_t) * TARGET_GDT_ENTRIES);
     g_free(obj);
 }
-- 
2.53.0