scsi: lpfc: Handle new link fault code returned by adapter firmware.

The driver encounters a link event ACQE with a fault code it doesn't
recognize, it logs an "Invalid" fault type and futher treats the unknown
value as a mailbox command failure.  First off, there is no "invalid"
value, only values that are unknown. Secondly, the fault code doesn't
indicate status - the rest of the ACQE contains that status so there is
no reason to "fail the commands".

Change the "Invalid" to "Unknown". There is no "invalid" code value.

Separate fault code parsing and message genaration from any mbx handling
status.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>