test: Adjust testCPUSecurityMitigations for images which default to nosmt
test: Adjust testCPUSecurityMitigations for images which default to nosmt

Fedora CoreOS enables the kernel "nosmt" option by default.

moraleslazaro/cockpit,cockpit-project/cockpit,mvollmer/cockpit,martinpitt/cockpit,garrett/cockpit,moraleslazaro/cockpit,garrett/cockpit,deryni/cockpit,cockpituous/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,cockpituous/cockpit,deryni/cockpit,martinpitt/cockpit,martinpitt/cockpit,mvollmer/cockpit,deryni/cockpit,cockpit-project/cockpit,garrett/cockpit,cockpit-project/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,garrett/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,deryni/cockpit,deryni/cockpit,deryni/cockpit,cockpituous/cockpit,deryni/cockpit,moraleslazaro/cockpit,garrett/cockpit,cockpit-project/cockpit,martinpitt/cockpit,cockpituous/cockpit,cockpit-project/cockpit,cockpituous/cockpit