[SCSI] libfc: fix handling of incoming Discover Address (ADISC) requests

The local port facility has been replying to ADISC requests without
looking to see if the remote port is logged in.  This is incorrect.
An ADISC request requires PLOGI first.  It should be rejected if
the sending remote port is not logged in.

This is like other incoming requests that require login, all of
which should be handled in the remote port module.

Move the ADISC request handling from fc_lport.c to fc_rport.c.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>