Revert "scsi: libfc: Add WARN_ON() when deleting rports"

This reverts commit bbc0f8bd

.

It added a warning whose intent was to check whether the rport was still
linked into the peer list. It doesn't work as intended and gives false
positive warnings for two reasons:

1) If the rport is never linked into the peer list it will not be
considered empty since the list_head is never initialized.

2) If the rport is deleted from the peer list using list_del_rcu(), then
the list_head is in an undefined state and it is not considered empty.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>