[PATCH] do_tty_hangup: use group_send_sig_info not send_group_sig_info

We already have the tasklist_lock so there is no need for us to reacquire it
with send_group_sig_info.  reader/writer locks allow multiple readers and thus
recursion so the old code was ok just wastful.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/char/tty_io.c

@@ -1094,8 +1094,8 @@ static void do_tty_hangup(void *data)
 				p->signal->tty = NULL;
 			if (!p->signal->leader)
 				continue;
-			send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
-			send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+			group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+			group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
 			if (tty->pgrp > 0)
 				p->signal->tty_old_pgrp = tty->pgrp;
 		} while_each_task_pid(tty->session, PIDTYPE_SID, p);