dev: Fix an IDE error check.

The error message says an IDE controller can support at most 4 disks, but the
check would fail if there were more than 3 disks.

Change-Id: Ic7d5d8c941fe2580da43019f53991377d4727bb9
Reviewed-on: https://gem5-review.googlesource.com/4460
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
1 file changed