Add two new trace events:
qxl_send_events(int qid, uint32_t events) "%d %d"
qxl_set_guest_bug(int qid) "%d"

Change qxl_io_unexpected_vga_mode parameters to be equivalent to those
of qxl_io_write for easier grouping under a single systemtap probe.

Change d to qxl in one place.
Signed-off-by: NAlon Levy <alevy@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>