Without this patch, the user has to add a kernel command line parameter
to get asynchronous SCSI scanning.  Now they can select the default at
compile time and still override it at boot time if they need to.
Signed-off-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>