drm/vmwgfx: Implement the cursor_set2 callback v2

Fixes native drm clients like Fedora 23 Wayland which now appears to
be able to use cursor hotspots without strange cursor offsets.
Also fixes a couple of ignored error paths.

Since the core drm cursor hotspot is incompatible with the legacy vmwgfx
hotspot (the core drm hotspot is reset when the drm_mode_cursor ioctl
is used), we need to keep track of both and add them when the device
hotspot is set. We assume that either is always zero.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
index bb63e4d..52caecb 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
@@ -297,7 +297,7 @@
 static struct drm_crtc_funcs vmw_legacy_crtc_funcs = {
 	.save = vmw_du_crtc_save,
 	.restore = vmw_du_crtc_restore,
-	.cursor_set = vmw_du_crtc_cursor_set,
+	.cursor_set2 = vmw_du_crtc_cursor_set2,
 	.cursor_move = vmw_du_crtc_cursor_move,
 	.gamma_set = vmw_du_crtc_gamma_set,
 	.destroy = vmw_ldu_crtc_destroy,