drm/vmwgfx: Clear uninitialized fields of a parameter

The uninitialized field is not currently used, but might be in the future,
and static analyzers complain.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NSinclair Yeh <syeh@vmware.com>
Reviewed-by: NCharmaine Lee <charmainel@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

@@ -757,7 +757,7 @@ static int vmw_create_dmabuf_proxy(struct drm_device *dev,
 				   struct vmw_surface **srf_out)
 {
 	uint32_t format;
-	struct drm_vmw_size content_base_size;
+	struct drm_vmw_size content_base_size = {0};
 	struct vmw_resource *res;
 	unsigned int bytes_pp;
 	struct drm_format_name_buf format_name;