Fix reference counting for Assembly

Use correct memory ordering.

Start the reference count at zero instead of one, thus giving us a
chance to actually deallocate something.

Remove remaining (unused) inclusions of cutils/atomic.h from
libpixelflinger.

Bug: 30838047

Change-Id: I3c6fd4a4861b3635cf398ca2aa3e915118100b10
4 files changed