[SCSI] mpt fusion: Cleanup some duplicate calls in mptbase.c

In mpt_detach, call to pci_set_drvdata is redundant because it
has already been called in mpt_adapter_disable. In mpt_attach,
ioc->pcidev is set to pdev two times.

Signed-off-by: Bandan Das <bandan.das@stratus.com>
Acked-by: "Desai, Kashyap" <Kashyap.Desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>