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/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index cb787c0..b11e997 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -92,7 +92,6 @@
 static void handle_rx_dm(struct uart_port *port, unsigned int misr)
 {
 	struct tty_port *tport = &port->state->port;
-	struct tty_struct *tty = tport->tty;
 	unsigned int sr;
 	int count = 0;
 	struct msm_port *msm_port = UART_TO_MSM(port);
@@ -138,7 +137,7 @@
 		count -= 4;
 	}
 
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(tport);
 	if (misr & (UART_IMR_RXSTALE))
 		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
@@ -148,7 +147,6 @@
 static void handle_rx(struct uart_port *port)
 {
 	struct tty_port *tport = &port->state->port;
-	struct tty_struct *tty = tport->tty;
 	unsigned int sr;
 
 	/*
@@ -191,7 +189,7 @@
 			tty_insert_flip_char(tport, c, flag);
 	}
 
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(tport);
 }
 
 static void reset_dm_count(struct uart_port *port)