pool: remove unneeded semicolon
bus.h: add missing include to linux/kref.h

Symptoms:
> kdbus/bus.h:56:14: error: field ‘kref’ has incomplete type
>   struct kref kref;

Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
test: test-kdbus: fix monitor and byebye tests

Since commit 7015a1e6 ("prevent special-purpose connections from
owning names or exchanging messages"), ioctl() calls return
-EOPNOTSUPP they are issued to a handle of a inapproprate type.
Follow this change in the test as well.
names: flush policy TALK cache when a connection loses a name

When a connection loses a name, make sure cache entries that allow
TALK access to it are properly removed. Upon the next TALK query,
the connection's names will be iterated and checked again.
policy: rename send_access_hash to talk_access_hash

We've already renamed the SEND policy to TALK for more clarity,
so let's do the same with the access hash.
policy, connection: rename policy cache related functions

Just so they reflect a little better what they're doing.