ART: Fix swap space free list
ART: Fix swap space free list

You should look for the element's size, not the freed size, when
coalescing nodes.

Bug: 18809642
Change-Id: I0c4396d52ef68f392f1e8c76a57e3fb5587b77fb

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst