Fix fcoe from_fabric_wwn
Fix fcoe from_fabric_wwn

Add comment for from_fabric_wwn to attempt to explain where all the
issues are coming from.

from_fabric_wwn is to convert tcm_fc wwn format to canonical. What's in
/sys/class/fc_host/.. is a different format and should be converted
to canonical separately.

Signed-off-by: Andy Grover <b7d524d2f5cc5aebadb6b92b08d3ab26911cde33@redhat.com>

cvubrugier/rtslib-fb,mikenawrocki/rtslib-fb,agrover/rtslib-fb,mikenawrocki/rtslib-fb