iommufd/selftest: Fix ioctl return value in _test_cmd_trigger_vevents()

The ioctl returns 0 upon success, so !0 returning -1 breaks the selftest.

Drop the '!' to fix it.

Fixes: 1d235d849425 ("iommu/selftest: prevent use of uninitialized variable")
Link: https://patch.msgid.link/r/20251014214847.1113759-1-nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
1 file changed