scsi: ibmvfc: Avoid unnecessary port relogin

Following an RSCN, ibmvfc will issue an ADISC to determine if the
underlying target has changed, comparing the SCSI ID, WWPN, and WWNN to
determine how to handle the rport in discovery. However, the comparison
of the WWPN and WWNN was performing a memcmp between a big endian field
against a CPU endian field, which resulted in the wrong answer on LE
systems. This was observed as unexpected errors getting logged at boot
time as targets were getting relogins when not needed.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>