serial: liteuart: move tty_flip_buffer_push() out of rx loop

Calling tty_flip_buffer_push() for each individual received character
is overkill. Move it out of the rx loop, and only call it once per
set of characters received together.
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20221123130500.1030189-7-gsomlo@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/liteuart.c

@@ -87,10 +87,10 @@ static void liteuart_timer(struct timer_list *t)
 		/* no overflow bits in status */
 		if (!(uart_handle_sysrq_char(port, ch)))
 			uart_insert_char(port, status, 0, ch, flg);
-
-		tty_flip_buffer_push(&port->state->port);
 	}
 
+	tty_flip_buffer_push(&port->state->port);
+
 	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
 }