Changes

xua_rkm: Fix dynamic AS destroyed when multiple ASPs are associated

If more than 1 ASP was assigned to a dynamic ASP, when one of the ASP
would go down it would incorrectly tear down the associated dynamic AS.
This is wrong and should only happen when the last of the ASPs
associated to the AS is destroyed.

Change-Id: I986044944282cea9a13ed59424f2220fee6fe567

asp: Log close&reconnect triggered from stream

This helps a lot in debugging the cascade of events happening when
something goes wrong, since the xua_cli_close_and_reconnect() is called
from several places.

Change-Id: I05ffa0b21ad7b694899982901d9b94bdcf4e7999

asp: Make sure asp->fi is set to NULL when freeing the object

The asp->fi is freed in lots of places through osmo_fsm_inst_term().
Make sure the pointer is actually set to NULL to catch potential
accesses to it after being freed.

Change-Id: I1e6a25f6db695a16bd05ae4ec481df6e14cf65b5

asp: Refactor osmo_ss7_asp_restart() into smaller chunks

This is a preparation patch towards fixing osmo_ss7_asp_restart() doing
too many things at the same time, like tearing down the stream, FSMs,
recreating them etc, not always in the best order.
This function split steps into functions, better ordering the steps in
the process.
For instance, when reopening the stream_cli, make sure to close it
beforehand. This would anyway be done inside osmo_stream_cli_open() but
then all events (and hence logging) even weird, due to disconnect_cb
triggering in the middle of the creation and then calling
osmo_ss7_asp_restart() again while it is being called.
The later will be fixed in a follow-up commit.

Change-Id: I5c3461b724924f528b46f7fe815f017a5b4a1ff5