[SCSI] fusion: add MSI support

On Mon, Jan 16, 2006 at 06:53:24PM -0700, Moore, Eric wrote:
> Adding MSI support, and command line for enabling
> it.  By default, the command line option has MSI disabled.

mpt_msi_enable is initialized to 0 implicitly, no need to do that.  Also
replace if (mpt_msi_enable == 1) tests with just if (mpt_msi_enable).

Updated patch below:

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>