This commit fixes a bug when using the UCT btl with the UCX memory
hooks disabled. We were misssing a call to
opal_mem_hooks_unregister_release to remove the btl memory hook
callback.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
(cherry picked from commit 36c206d2d616578c97853d1d69727a1d6e165c1e)
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>