[SCSI] libfc: fix rport error handling for login-required and invalid ops

When receiving an ELS request, if the request isn't recognized,
the unsupported operation error should be given even if the port
is not found or not logged in.

Also, the LOGO request shouldn't give the login-required explanation.

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>