serial_core: fix sizeof(pointer)

sizeof when applied to a pointer typed expression gives the
size of the pointer.

Generated by: scripts/coccinelle/misc/noderef.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_core.c

@@ -640,7 +640,7 @@ static void uart_get_info(struct tty_port *port,
 {
 	struct uart_port *uport = state->uart_port;
 
-	memset(retinfo, 0, sizeof(retinfo));
+	memset(retinfo, 0, sizeof(*retinfo));
 
 	retinfo->type	    = uport->type;
 	retinfo->line	    = uport->line;