exit/rtl8723bs: Replace the macro thread_exit with a simple return 0

Every place thread_exit is called is at the end of a function started
with kthread_run.  The code in kthread_run has arranged things so a
kernel thread can just return and do_exit will be called.

So just have the threads return instead of calling complete_and_exit.

Link: https://lkml.kernel.org/r/20211020174406.17889-18-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

drivers/staging/rtl8723bs/core/rtw_cmd.c

@@ -524,7 +524,7 @@ post_process:
 	complete(&pcmdpriv->terminate_cmdthread_comp);
 	atomic_set(&(pcmdpriv->cmdthd_running), false);
 
-	thread_exit();
+	return 0;
 }
 
 /*

drivers/staging/rtl8723bs/core/rtw_xmit.c

@@ -2491,7 +2491,7 @@ int rtw_xmit_thread(void *context)
 
 	complete(&padapter->xmitpriv.terminate_xmitthread_comp);
 
-	thread_exit();
+	return 0;
 }
 
 void rtw_sctx_init(struct submit_ctx *sctx, int timeout_ms)

drivers/staging/rtl8723bs/hal/rtl8723bs_xmit.c

@@ -435,7 +435,7 @@ int rtl8723bs_xmit_thread(void *context)
 
 	complete(&pxmitpriv->SdioXmitTerminate);
 
-	thread_exit();
+	return 0;
 }
 
 s32 rtl8723bs_mgnt_xmit(

drivers/staging/rtl8723bs/include/osdep_service_linux.h

@@ -45,8 +45,6 @@
 		spinlock_t	lock;
 	};
 
-	#define thread_exit() complete_and_exit(NULL, 0)
-
 static inline struct list_head *get_next(struct list_head	*list)
 {
 	return list->next;