[SCSI] megaraid_{mm,mbox}: a fix on INQUIRY with EVPD

With this patch, driver will protect data corruption created by
INQUIRY with EVPD request to megaraid controllers.  As specified in
the changelog, megaraid F/W already has fixed the issue and being
under process of release. Meanwhile, driver will protect the system
with this patch.

Signed-Off By: Seokmann Ju <seokmann.ju@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>