bufferpool2: handle transfer to closed connection

Handle transfer to closed connection properly. Also avoid spinlocking
during invalidation.

Bug: 139506073
Test: atest CtsMediaTestCases -- --module-arg CtsMediaTestCases:size:small
Merged-In: I9037ab0bde48a51b2b97158ecd0086dac84f8b26
Change-Id: I9037ab0bde48a51b2b97158ecd0086dac84f8b26
4 files changed