mcctl.c: Null pointer passed as an argument to a 'nonnull' parameter
mcctl.c: Null pointer passed as an argument to a 'nonnull' parameter

Fix issue reported by Clang Static Analyzer:

    File:        memcached/programs/mcctl/mcctl.c
    Location:    line 165, column 13
    Description: Null pointer passed as an argument to a 'nonnull' parameter

Change-Id: Iaacfbbc5e6f38b7830843d2e3cb9f74445cc3b66
Reviewed-on: http://review.couchbase.org/57856
Well-Formed: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

daverigby/memcached,daverigby/memcached,couchbase/memcached,daverigby/kv_engine,daverigby/memcached,daverigby/kv_engine,owendCB/memcached,owendCB/memcached,daverigby/memcached,couchbase/memcached,owendCB/memcached,daverigby/kv_engine,couchbase/memcached,owendCB/memcached,couchbase/memcached,daverigby/kv_engine