ctdb-server: Add some local variables

ctdb-server: Add some local variables

Improve readability by not repeating the complex expression now
assigned to addr.  ctdb_sys_have_ip() is called in both arms of the
if/else, so call it once when declaring the new variable.

Modernise debug macros while touching lines.

Signed-off-by: Martin Schwenke <mschwenke@ddn.com>
Reviewed-by: John Mulligan <jmulligan@redhat.com>
Reviewed-by: Anoop C S <anoopcs@samba.org>