[SCSI] mpt2sas: fix oops because drv data points to NULL on resume from hibernate

Fix another ocurring when the system resumes.  This oops was due to driver
setting the pci drvdata to NULL on the prior hibernation.  Becuase it was
set to NULL, upon resmume we assume the pci drvdata is non-zero, and we oops.
To fix the ooops, we don't set pci drvdata to NULL at hibernation time.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>