[SCSI] libfc: defer releasing master lport until complete fcoe interface cleanuped up

The fcoe controller has back references, therefore defer
releasing master lport which gets freed along scsi_host_put
and then free it once fcoe interface is fully cleaned.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>