util: fix os_create_anonymous_file on android

Commit fixes current crashes with Vulkan applications on Android.

Fixes: c0376a12 "util: add anon_file.h for all memfd/temp file usage"
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
(cherry picked from commit ce8fd042)