lib: trusty: Assert that at most one handle gets deleted am: 3268d1221e

Original change: https://android-review.googlesource.com/c/trusty/lk/trusty/+/3529080

Change-Id: Ieee2cd39634a23755d9c90bf3940772f2d25c636
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>