[SCSI] mpt: fix disable lsi sas to use msi as default

Impact: fix bug

the third param in module_param(,,) is perm instead of default value.
we still need to assign default at first.  Also, the default is now
zero not one, so fix the parameter text to reflect that.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Kashyap Desai <kadesai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>