chardev: mark explicitly first argument as poisoned

Since commit 9894dc0cdc "char: convert
from GIOChannel to QIOChannel", the first argument to the watch callback
can actually be a QIOChannel, which is not a GIOChannel (but a QEMU
Object).

Even though we never used that pointer, change the callback type to warn
the users. Possibly a better fix later, we may want to store the
callback and call it from intermediary functions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

hw/char/cadence_uart.c

@@ -288,7 +288,7 @@ static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
     uart_update_status(s);
 }
 
-static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond,
+static gboolean cadence_uart_xmit(void *do_not_use, GIOCondition cond,
                                   void *opaque)
 {
     CadenceUARTState *s = opaque;

hw/char/cmsdk-apb-uart.c

@@ -191,7 +191,7 @@ static uint64_t uart_read(void *opaque, hwaddr offset, unsigned size)
 /* Try to send tx data, and arrange to be called back later if
  * we can't (ie the char backend is busy/blocking).
  */
-static gboolean uart_transmit(GIOChannel *chan, GIOCondition cond, void *opaque)
+static gboolean uart_transmit(void *do_not_use, GIOCondition cond, void *opaque)
 {
     CMSDKAPBUART *s = CMSDK_APB_UART(opaque);
     int ret;

hw/char/ibex_uart.c

@@ -135,7 +135,7 @@ static void ibex_uart_receive(void *opaque, const uint8_t *buf, int size)
     ibex_uart_update_irqs(s);
 }
 
-static gboolean ibex_uart_xmit(GIOChannel *chan, GIOCondition cond,
+static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
                                void *opaque)
 {
     IbexUartState *s = opaque;

hw/char/nrf51_uart.c

@@ -75,7 +75,7 @@ static uint64_t uart_read(void *opaque, hwaddr addr, unsigned int size)
     return r;
 }
 
-static gboolean uart_transmit(GIOChannel *chan, GIOCondition cond, void *opaque)
+static gboolean uart_transmit(void *do_not_use, GIOCondition cond, void *opaque)
 {
     NRF51UARTState *s = NRF51_UART(opaque);
     int r;

hw/char/serial.c

@@ -220,7 +220,7 @@ static void serial_update_msl(SerialState *s)
     }
 }
 
-static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond,
+static gboolean serial_watch_cb(void *do_not_use, GIOCondition cond,
                                 void *opaque)
 {
     SerialState *s = opaque;

hw/char/virtio-console.c

@@ -38,7 +38,7 @@ struct VirtConsole {
  * Callback function that's called from chardevs when backend becomes
  * writable.
  */
-static gboolean chr_write_unblocked(GIOChannel *chan, GIOCondition cond,
+static gboolean chr_write_unblocked(void *do_not_use, GIOCondition cond,
                                     void *opaque)
 {
     VirtConsole *vcon = opaque;