target/tcm_fc: Rename structs and list members for clarity

Rename struct ft_lport_acl to ft_lport_wwn. "acl" is associated with
something different in LIO terms. Really, ft_lport_wwn is the
fabric-specific wrapper for the struct se_wwn.

Rename "lacl" local variables to "ft_wwn" as well.

Rename list_heads used as list members to make it clear they're nodes, not
heads.

Rename lport_node to ft_wwn_node.

Rename ft_lport_list to ft_wwn_list

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>