Ticket 48805 - Sign comparison checks.
    
    Description: commit 3e7d6d62f3b2889d0250cb0a3892982e42ada878
    introduced a compiler warnng in dbscan.c.
    - warning: format ‘%d’ expects argument of type ‘int’, but argument 2
               has type ‘size_t {aka long unsigned int}’
    
    Reviewed by nhosoi (one line commit rule)