[SCSI] qla2xxx: Don't perform a BIG_HAMMER if Get-ID (0x20) mailbox command fails on CNAs.

The semantics we employ now in the driver, performing a
BIG_HAMMER in the event of Get-ID (0x20) mailbox command
failing, should only be done for FC.  On FC configurations, it
makes sense since advertising is only really performed once,
so a BIG_HAMMER to reinitiate the process is needed to
restart.  Under FCoE, this is not needed, as there's a
continous stream of advertisements/ACks at the protocol layer
to initiate a relogin/reinitialization process.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>