ctdb-tests: Use known install paths in local daemon tests

ctdb-tests: Use known install paths in local daemon tests

The in-tree local daemons tests don't work from a top-level Samba
compile.  The simple test suite was the first test suite and things
have generally worked, so it has been slow to adopt general test
infrastructure changes.

Instead of re-calculating script and helper locations, use the paths
from script_install_paths.sh.  The bin/ directory is already added to
PATH in common.sh, so don't add it here.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>