Explicitly specify tcmalloc dll to get function addresses
Explicitly specify tcmalloc dll to get function addresses

Also, use #ifdef instead of #ifndef to make it more straightforward.

Change-Id: Ib61fa60640051af55983e2cfb44e07fe3db460e1
Reviewed-on: http://review.couchbase.org/14637
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>

cloudrain21/memcached-1,daverigby/memcached,couchbase/memcached,cloudrain21/memcached-1,jimwwalker/memcached,abhinavdangeti/memcached,owendCB/memcached,abhinavdangeti/memcached,mrkwse/memcached,owendCB/memcached,daverigby/kv_engine,jimwwalker/memcached,abhinavdangeti/memcached,daverigby/kv_engine,mrkwse/memcached,daverigby/memcached,daverigby/memcached,abhinavdangeti/memcached,abhinavdangeti/memcached,owendCB/memcached,cloudrain21/memcached-1,mrkwse/memcached,couchbase/memcached,jimwwalker/memcached,cloudrain21/memcached-1,owendCB/memcached,couchbase/memcached,couchbase/memcached,daverigby/kv_engine,daverigby/memcached,daverigby/kv_engine,mrkwse/memcached