Revert "Fix return error."

This reverts commit 9ce7bfa3.

Reason for revert: should check whether the allocated buffer count is the same as requested buffer count, rather than not equals zero. This is because there is a use case when bufferhub queue is created without allocated buffers.

Bug: 115573986

Change-Id: I5a0dc67e6631248a019f3af95b801e2bb7f6d6be