iscsid: Fix strlen parameter

The target socket name is passed as parameter, don't use the hardwired
one.

Signed-off-by: Jan Vesely <jvesely@redhat.com>
iscsiuio: Change socket bind to use the same struct size as iscsid

Without this patch connections to iscsiuio fail, and strace prints:

connect(8, {sa_family=AF_FILE, path=@"ISCSID_UIP_ABSTRACT_NAMESPACE"}, 32) = -1 ECONNREFUSED (Connection refused)

Note that updating mgmt_ipc_listen and ipc_connect to use sizeof(addr) instead
of the precomputed values also fixes the issue.
Looks like "(Null bytes in the name have no special significance.)" [man 7 unix] is the culprit here.

Signed-off-by: Jan Vesely <jvesely@redhat.com>