gdbstub: drop CPUEnv from gdb_exit()

gdb_exit() has never needed anything from env and I doubt we are going
to start now.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210108224256.2321-8-alex.bennee@linaro.org>
diff --git a/gdbstub.c b/gdbstub.c
index aeffdaf..a4718d4 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -3068,7 +3068,7 @@
 }
 
 /* Tell the remote gdb that the process has exited.  */
-void gdb_exit(CPUArchState *env, int code)
+void gdb_exit(int code)
 {
   char buf[4];