tools/liblockdep: Remove debug print left over from development

Remove a debug print in init_preload() which was left over from
development and isn't usefull at all currently. It was also causing
false positive test results.

Reported-by: S. Lockwood-Childs <sjl@vctlabs.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>