accel/tcg: Replace CPUState.env_ptr with cpu_env()

Reviewed-by: Anton Johansson <anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/gdbstub/user-target.c b/gdbstub/user-target.c
index 6e21c31..c4bba4c 100644
--- a/gdbstub/user-target.c
+++ b/gdbstub/user-target.c
@@ -310,7 +310,7 @@
     uint64_t mode = get_param(params, 2)->val_ull;
 
 #ifdef CONFIG_LINUX
-    int fd = do_guest_openat(gdbserver_state.g_cpu->env_ptr, 0, filename,
+    int fd = do_guest_openat(cpu_env(gdbserver_state.g_cpu), 0, filename,
                              flags, mode, false);
 #else
     int fd = open(filename, flags, mode);