[SCSI] qla2xxx: Correct MQ-chain information retrieval during a firmware dump.

Original code would not read request/response queue pointers.
Also, collapse code into a helper qla25xx_copy_mq() function in
preparation for newer ISP parts.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>