recoverd: takeover_run_core() should not use modified node flags

recoverd: takeover_run_core() should not use modified node flags

Modifying the node flags with IP-allocation-only flags is not
necessary.  It causes breakage if the flags are not cleared after use.
ctdb_takeover_run() no longer needs the general node flags - it only
needs the IP flags.

Instead of modifying the node flags in nodemap, construct a custom IP
flags list and have takeover_run_core() use that instead of node
flags.  As well as being safer, this makes the IP allocation code more
self contained and a little bit clearer.

Signed-off-by: Martin Schwenke <martin@meltin.net>
(This used to be ctdb commit 14bd0b6961ef1294e9cba74ce875386b7dfbf446)