tty: tty_io: Fix trailing whitespace issues

Fix trailing whitespace issues, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-10-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -3015,7 +3015,7 @@ static int this_tty(const void *t, struct file *file, unsigned fd)
 		return 0;
 	return file_tty(file) != t ? 0 : fd + 1;
 }
-	
+
 /*
  * This implements the "Secure Attention Key" ---  the idea is to
  * prevent trojan horses by killing all processes associated with this