Fix return error

Previously, the allocate buffer does not return error if it runs out of
memory. This change adds the error in return.

Test: buffer_hub_queue-test passes on Vega on oc-dr1-daydream-dev branch
Test: buffer_hub_queue-test passes on Marlin on master branch
Bug: None

Change-Id: I2a37fd3221cf54c92d4f53e577e5f0055ef77b13