TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 41b75c5..2f58e9f 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -413,7 +413,7 @@
 			case CTRLCHAR_CTRL:
 				tty_insert_flip_char(&raw->port, cchar,
 						TTY_NORMAL);
-				tty_flip_buffer_push(tty);
+				tty_flip_buffer_push(&raw->port);
 				break;
 
 			case CTRLCHAR_NONE:
@@ -427,7 +427,7 @@
 					count -= 2;
 				tty_insert_flip_string(&raw->port, raw->inbuf,
 						count);
-				tty_flip_buffer_push(tty);
+				tty_flip_buffer_push(&raw->port);
 				break;
 			}
 		} else if (req->type == RAW3215_WRITE) {