The build.rs had supported placing bindings.inc.rs in rust/qemu-api/src,
but this "not encouraged" feature is broken.
Considering that manually copying bindings.inc.rs to the development
directory is also useful, fix the bindings.inc.rs path generation to
give this feature another chance.
Fixes: commit 1ae4ca0463 ("rust: move rust.bindgen to qemu-api crate")
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250623073436.1833357-1-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
bffbb430ee