Allow IAT patches to fail when patching for Active Verifier.

Not all loaded modules import CloseHandle and DuplicateHandle so
InstallHandleHooks was failing incorrectly and causing the Handle
Verifier to be disabled.

Also, continue to patch DuplicateHandle if a module happens to
not import CloseHandle.

BUG=570912

Review URL: https://codereview.chromium.org/1540723002

Cr-Commit-Position: refs/heads/master@{#366322}
2 files changed