usb: gadget: serial: %pf is only for function pointers

Use %ps for actual addresses, otherwise you'll get bad output
on arches like ppc64 where %pf expects a function descriptor
(which is not what __builtin_return_address returns).

Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: linux-usb@vger.kernel.org
CC: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/u_serial.c

@@ -912,7 +912,7 @@ static int gs_put_char(struct tty_struct *tty, unsigned char ch)
 	unsigned long	flags;
 	int		status;
 
-	pr_vdebug("gs_put_char: (%d,%p) char=0x%x, called from %pf\n",
+	pr_vdebug("gs_put_char: (%d,%p) char=0x%x, called from %ps\n",
 		port->port_num, tty, ch, __builtin_return_address(0));
 
 	spin_lock_irqsave(&port->port_lock, flags);