ANDROID: binder: correct the cmd print for BINDER_WORK_RETURN_ERROR

When to execute binder_stat_br the e->cmd has been modifying as BR_OK
instead of the original return error cmd, in fact we want to know the
original return error, such as BR_DEAD_REPLY or BR_FAILED_REPLY, etc.
instead of always BR_OK, in order to avoid the value of the e->cmd is
always BR_OK, so we need assign the value of the e->cmd to cmd before
e->cmd = BR_OK.

Signed-off-by: songjinshi <songjinshi@xiaomi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder.c

@@ -3921,10 +3921,11 @@ static int binder_thread_read(struct binder_proc *proc,
 			binder_inner_proc_unlock(proc);
 			if (put_user(e->cmd, (uint32_t __user *)ptr))
 				return -EFAULT;
+			cmd = e->cmd;
 			e->cmd = BR_OK;
 			ptr += sizeof(uint32_t);
 
-			binder_stat_br(proc, thread, e->cmd);
+			binder_stat_br(proc, thread, cmd);
 		} break;
 		case BINDER_WORK_TRANSACTION_COMPLETE: {
 			binder_inner_proc_unlock(proc);