serial: sh-sci: Improve type-safety calling sci_receive_chars()

While ptr and port both point to the uart_port structure, the former is
the untyped pointer cookie passed to interrupt handlers.
Use the correctly typed port variable instead, to improve type-safety.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sh-sci.c

@@ -1693,7 +1693,7 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
 	 * to be disabled?
 	 */
-	sci_receive_chars(ptr);
+	sci_receive_chars(port);
 
 	return IRQ_HANDLED;
 }
@@ -1749,7 +1749,7 @@ static irqreturn_t sci_er_interrupt(int irq, void *ptr)
 	} else {
 		sci_handle_fifo_overrun(port);
 		if (!s->chan_rx)
-			sci_receive_chars(ptr);
+			sci_receive_chars(port);
 	}
 
 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));