6977d7c TOOLS: Fix minor memory leak in sss_colondb_writeline

Authored and Committed by lslebodn 8 years ago
    TOOLS: Fix minor memory leak in sss_colondb_writeline
    
    The variable line was initialized to NULL.
    The we created temporary context tmp_ctx.
    We use talloc_asprintf_append to append string to line which is initially
    NULL and therefore new context which was not connected to tmp_ctx.
        man 3 talloc_string -> talloc_asprintf_append
    
    Reviewed-by: Petr Cech <pcech@redhat.com>