[vulkan] Remove call to zxio_create

Removes an instance of fidl multiplexing,
where a channel is used for both the
and the fuchsia_io::Node protocols.
This behavior is invoked through the zxio_create call.

The zxio_create call can be removed, because the
Vulkan loader should guarantee that the device exists.

Bug: 42063787

Testing: This is tested in all aemu vulkan tests.
Change-Id: I03a8f670a6c7fb8f5417f19ec38dd5cd38aca900
1 file changed