[SCSI] fcoe: remove check for zero fabric name

This check prevents FCF selection in NPV mode due to zero fabric name
in that case and in turn flogi fails. Though NPV mode should not have
this zero and should be fixed there also but spec also does not require
initiator to ensure that fabric name must be non-zero, therefore dropping
this check to get flogi working in NPV mode.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>