rxrpc: Move client call connection to the I/O thread

jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-284.30.1.el9_2
commit-author David Howells <dhowells@redhat.com>
commit 9d35d88
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
Will be included in final tarball splat. Ref for failed cherry-pick at:
ciq/ciq_backports/kernel-5.14.0-284.30.1.el9_2/9d35d880.failed

Move the connection setup of client calls to the I/O thread so that a whole
load of locking and barrierage can be eliminated.  This necessitates the
app thread waiting for connection to complete before it can begin
encrypting data.

This also completes the fix for a race that exists between call connection
and call disconnection whereby the data transmission code adds the call to
the peer error distribution list after the call has been disconnected (say
by the rxrpc socket getting closed).

The fix is to complete the process of moving call connection, data
transmission and call disconnection into the I/O thread and thus forcibly
serialising them.

Note that the issue may predate the overhaul to an I/O thread model that
were included in the merge window for v6.2, but the timing is very much
changed by the change given below.

Fixes: cf37b59 ("rxrpc: Move DATA transmission into call processor work item")
	Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com
	Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
(cherry picked from commit 9d35d88)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

# Conflicts:
#	include/trace/events/rxrpc.h
#	net/rxrpc/ar-internal.h
#	net/rxrpc/call_object.c
#	net/rxrpc/call_state.c
#	net/rxrpc/conn_client.c
#	net/rxrpc/conn_event.c
#	net/rxrpc/conn_object.c
#	net/rxrpc/io_thread.c
#	net/rxrpc/local_object.c
#	net/rxrpc/rxkad.c
#	net/rxrpc/security.c
#	net/rxrpc/sendmsg.c

Author: PlaidCat