drm/vmwgfx: Fix depth input into drm_mode_legacy_fb_format

Currently the pitch is passed in as depth.  This causes
drm_mode_legacy_fb_format() to return the wrong pixel format.

The wrong pixel format will be rejected by vmw_kms_new_framebuffer(),
thus leaving par->set_fb to NULL.

This eventually causes a crash in vmw_fb_setcolreg() when the code
tries to dereference par->set_fb.

Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_fb.c

@@ -481,8 +481,7 @@ static int vmw_fb_kms_framebuffer(struct fb_info *info)
 	mode_cmd.height = var->yres;
 	mode_cmd.pitches[0] = ((var->bits_per_pixel + 7) / 8) * mode_cmd.width;
 	mode_cmd.pixel_format =
-		drm_mode_legacy_fb_format(var->bits_per_pixel,
-			((var->bits_per_pixel + 7) / 8) * mode_cmd.width);
+		drm_mode_legacy_fb_format(var->bits_per_pixel, depth);
 
 	cur_fb = par->set_fb;
 	if (cur_fb && cur_fb->width == mode_cmd.width &&