ZOOKEEPER-3078: remove print_completion_queue
ZOOKEEPER-3078: remove print_completion_queue

The fprintf(LOGSTREAM, ...) calls cause compiler errors when building
with GCC 8: "error: null argument where non-null required".  This is
because since ZOOKEEPER-1400 (2013-05-19 commit 37973fab: Allow logging
via callback instead of raw FILE pointer) LOGSTREAM is defined as NULL.
However, the last use of print_completion_queue was removed 2008-01-10
in commit ffc4b0d4 (Changed zoo_get() signature, changed the watcher
callback signature, fixed zookeeper_close() resource leaks and race
conditions, fixed the race condition causing xid mismatch).  So we can
avoid the compiler errors by just removing print_completion_queue.

Signed-off-by: Kent R. Spillner <kspillneracm.org>

Author: Kent R. Spillner <kspillner@acm.org>

Reviewers: Norbert Kalmar <nkalmar@cloudera.com>, Andor Molnár <andor@apache.org>, Benjamin Reed <breed@apache.org>

Closes #558 from sl4mmy/zookeeper-3078

hanm/zookeeper,apache/zookeeper,apache/zookeeper,apache/zookeeper,hanm/zookeeper,arshadmohammad/zookeeper,arshadmohammad/zookeeper,hanm/zookeeper,arshadmohammad/zookeeper,apache/zookeeper,apache/zookeeper,arshadmohammad/zookeeper,apache/zookeeper,hanm/zookeeper,arshadmohammad/zookeeper,maoling/zookeeper,maoling/zookeeper,arshadmohammad/zookeeper,apache/zookeeper,hanm/zookeeper,hanm/zookeeper,hanm/zookeeper,apache/zookeeper,maoling/zookeeper,arshadmohammad/zookeeper,maoling/zookeeper,maoling/zookeeper,hanm/zookeeper,maoling/zookeeper,arshadmohammad/zookeeper,maoling/zookeeper,maoling/zookeeper