audio: Do not delete PatchRecord before Peer is stopped

PatchPanel::clearPatchConnections deletes PatchRecord before
the peer PatchTrack is stopped. This can cause an access to already
free'ed memory leading to a crash in PatchTrack::getNextBuffer.

Fix is to delete PatchRecord and PatchTrack only after removing
both of them from active tracks list

Bug: 22304526.
Change-Id: I7003756d3d2dd8912ce5e3b2fc31f5e82f455888