serial: 8250_pci: make setup_port() parameters explicitly unsigned

The bar and offset parameters to setup_port() are used in pointer math,
and while it would be very difficult to get them to wrap as a negative
number, just be "safe" and make them unsigned so that static checkers do
not trip over them unintentionally.

Cc: Jiri Slaby <jirislaby@kernel.org>
Reported-by: Jordy Zomer <jordy@pwning.systems>
Link: https://lore.kernel.org/r/20210726130717.2052096-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_pci.c

@@ -87,7 +87,7 @@ static void moan_device(const char *str, struct pci_dev *dev)
 
 static int
 setup_port(struct serial_private *priv, struct uart_8250_port *port,
-	   int bar, int offset, int regshift)
+	   u8 bar, unsigned int offset, int regshift)
 {
 	struct pci_dev *dev = priv->dev;