vnc: move check into vnc_cursor_define

Move the check whenever a cursor exists into the vnc_cursor_define()
function so callers don't have to do it.

Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20210112134120.2031837-2-kraxel@redhat.com

ui/vnc.c

@@ -793,9 +793,7 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
     QTAILQ_FOREACH(vs, &vd->clients, next) {
         vnc_colordepth(vs);
         vnc_desktop_resize(vs);
-        if (vs->vd->cursor) {
-            vnc_cursor_define(vs);
-        }
+        vnc_cursor_define(vs);
         memset(vs->dirty, 0x00, sizeof(vs->dirty));
         vnc_set_area_dirty(vs->dirty, vd, 0, 0,
                            vnc_width(vd),
@@ -929,6 +927,10 @@ static int vnc_cursor_define(VncState *vs)
     QEMUCursor *c = vs->vd->cursor;
     int isize;
 
+    if (!vs->vd->cursor) {
+        return -1;
+    }
+
     if (vnc_has_feature(vs, VNC_FEATURE_ALPHA_CURSOR)) {
         vnc_lock_output(vs);
         vnc_write_u8(vs,  VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
@@ -2155,9 +2157,7 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
     vnc_desktop_resize(vs);
     check_pointer_type_change(&vs->mouse_mode_notifier, NULL);
     vnc_led_state_change(vs);
-    if (vs->vd->cursor) {
-        vnc_cursor_define(vs);
-    }
+    vnc_cursor_define(vs);
 }
 
 static void set_pixel_conversion(VncState *vs)