ppp: Fix typo in comment

Delete the redundant word 'the'.

Signed-off-by: Xiang wangx <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ppp/ppp_generic.c

···
 	chan->ppp = NULL;
 
 	/*
-	 * This ensures that we have returned from any calls into the
+	 * This ensures that we have returned from any calls into
 	 * the channel's start_xmit or ioctl routine before we proceed.
 	 */
 	down_write(&pch->chan_sem);