scsi: qla2xxx: Silent erroneous message

Driver uses shadow pointer instead of Mirror pointer for firmware dump
collection. Skip those entries for Mirror pointers for Request/Response
queue from firmware dump template reading.

Following messages are printed in log messages:

 qla27xx_fwdt_entry_t268: unknown buffer 4
 qla27xx_fwdt_entry_t268: unknown buffer 5

This patch fixes these error messages by adding skip_entry() to not read
them from template.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>